7. Debt of the Operating Partnership

A summary of outstanding indebtedness of the Operating Partnership as of December 31, 2013 and 2012 is as follows (in thousands):



Indebtedness	Interest Rate at December 31, 2013		Maturity Date		Principal Outstanding December 31, 2013		Principal Outstanding December 31, 2012
Global revolving credit facility	Various	(1)	Nov. 3, 2017		$ 724,668	(2)	$ 723,729	(2)

Unsecured term loan	Various	(3)(9)	Apr. 16, 2017		$ 1,020,984	(4)	$ 757,839	(4)

Unsecured senior notes:
Prudential Shelf Facility:
Series B	9.320%		Nov. 5, 2013		-	(13)	33,000
Series C	9.680%		Jan. 6, 2016		25,000		25,000
Series D	4.570%		Jan. 20, 2015		50,000		50,000
Series E	5.730%		Jan. 20, 2017		50,000		50,000
Series F	4.500%		Feb. 3, 2015		17,000		17,000
Total Prudential Shelf Facility					142,000		175,000
Senior Notes:
4.50% notes due 2015	4.500%		Jul. 15, 2015		375,000		375,000
5.875% notes due 2020	5.875%		Feb. 1, 2020		500,000		500,000
5.25% notes due 2021	5.250%		Mar. 15, 2021		400,000		400,000
3.625% notes due 2022	3.625%		Oct. 1, 2022		300,000		300,000
4.25% notes due 2025	4.250%		Jan. 17, 2025		662,280	(10)	-
Unamortized discounts					(15,048)		(11,779)
Total senior notes, net of discount					2,222,232		1,563,221

Total unsecured senior notes, net of discount					2,364,232		1,738,221

Exchangeable senior debentures:

5.50% exchangeable senior debentures due 2029	5.500%		Apr. 15, 2029	(5)	266,400		266,400

Total exchangeable senior debentures					266,400		266,400


Indebtedness	Interest Rate at December 31, 2013		Maturity Date	Principal Outstanding December 31, 2013		Principal Outstanding December 31, 2012

Mortgage loans:
Secured Term Debt (6)(7)	5.65%		Nov. 11, 2014	132,966		135,991
200 Paul Avenue (7)	5.74%		Oct. 8, 2015	70,713		72,646
Mundells Roundabout	3-month GBP LIBOR + 1.20%	(9)	Nov. 30, 2013	-	(13)	69,612	(10)
2045 & 2055 LaFayette Street (7)	5.93%		Feb. 6, 2017	63,623		64,621
34551 Ardenwood Boulevard 1-4 (7)	5.95%		Nov. 11, 2016	52,152		52,916
1100 Space Park Drive (7)	5.89%		Dec. 11, 2016	52,115		52,889
600 West Seventh Street	5.80%		Mar. 15, 2016	49,548		51,174
150 South First Street (7)	6.30%		Feb. 6, 2017	50,097		50,830
360 Spear Street (7)	6.32%		Nov. 8, 2013	-	(13)	46,613
Clonshaugh Industrial Estate II (8)	3-month EURIBOR + 4.50%		Sep. 4, 2014	-	(13)	39,579	(11)
2334 Lundy Place (7)	5.96%		Nov. 11, 2016	37,930		38,486
1500 Space Park Drive (7)	6.15%		Oct. 5, 2013	-	(13)	35,682
Cressex 1 (12)	5.68%		Oct. 16, 2014	28,583	(10)	28,560	(10)
636 Pierce Street	5.27%		Apr. 15, 2023	26,327		-
Paul van Vlissingenstraat 16	3-month EURIBOR + 1.60%	(9)	Jul. 18, 2013	-	(13)	13,336	(11)
Chemin de l'Epinglier 2	3-month EURIBOR + 1.50%	(9)	Jul. 18, 2013	-	(13)	9,649	(11)
Gyroscoopweg 2E-2F	3-month EURIBOR + 1.50%	(9)	Oct. 18, 2013	-	(13)	8,492	(11)
Manchester Technopark (12)	5.68%		Oct. 16, 2014	8,695	(10)	8,688	(10)
8025 North Interstate 35	4.09%		Mar. 6, 2016	6,314		6,561
731 East Trade Street	8.22%		Jul. 1, 2020	4,186		4,509
Unamortized net premiums				2,359		1,542

Total mortgage loans, net of premiums				585,608		792,376

Total indebtedness				$ 4,961,892		$ 4,278,565

(1)

The interest rate for borrowings under the global revolving credit facility equals the applicable index plus a margin of 110 basis points, which is based on the credit rating of our long-term debt. An annual facility fee of 20 basis points, which is based on the credit rating of our long-term debt, is due and payable quarterly on the total commitment amount of the facility. Two six-month extensions are available, which we may exercise if certain conditions are met.


2)	Balances as of December 31, 2013 and December 31, 2012 are as follows (balances, in thousands):



Denomination of Draw	Balance as of December 31, 2013		Weighted-average interest rate	Balance as of December 31, 2012		Weighted-average interest rate

Floating Rate Borrowing (a)

U.S. dollar ($)	$ 466,000		1.27%	$ 35,000		1.47%
British pound sterling (£)	-		-	433,195	(d)	1.75%
Euro (€)	78,335	(c)	1.33%	87,074	(d)	1.36%
Singapore dollar (SGD)	-		-	26,191	(d)	1.56%
Australian dollar (AUD)	67,212	(c)	3.70%	93,754	(d)	4.42%
Hong Kong dollar (HKD)	57,390	(c)	1.31%	34,515	(d)	1.53%
Japanese yen (JPY)	12,858	(c)	1.21%	-		-
Canadian dollar (CAD)	14,873	(c)	2.32%	-		-
Total	$ 696,668		1.53%	$ 709,729		2.02%

Base Rate Borrowing (b)

U.S. dollar ($)	$ 28,000		3.35%	$ 14,000		3.50%

Total borrowings	$ 724,668		1.60%	$ 723,729		2.05%


	(a)	The interest rates for floating rate borrowings under the global revolving credit facility equal the applicable index plus a margin of 110 basis points and 125 basis points as of December 31, 2013 and 2012, respectively, which are based on the credit rating of our long-term debt.
	(b)	The interest rates for base rate borrowings under the global revolving credit facility equal the U.S. Prime Rate plus a margin of 10 basis points and 25 basis points as of December 31, 2013 and 2012, respectively, which are based on the credit rating of our long-term debt.
	(c)	Based on exchange rates of $1.37 to €1.00, $0.89 to 1.00 AUD, $0.13 to 1.00 HKD, $0.01 to 1.00 JPY and $0.94 to 1.00 CAD, respectively, as of December 31, 2013.
	(d)	Based on exchange rates of $1.63 to £1.00, $1.32 to €1.00, $0.82 to 1.00 SGD, $1.04 to 1.00 AUD and $0.13 to 1.00 HKD, respectively, as of December 31, 2012.


(3)	Interest rates are based on our senior unsecured debt ratings and are 120 basis points and 145 basis points over the applicable index for floating rate advances as of December 31, 2013 and 2012, respectively. Two six-month extensions are available, which we may exercise if certain conditions are met.


(4)	Balances as of December 31, 2013 and December 31, 2012 are as follows (balances, in thousands):


Denomination of Draw	Balance as of December 31, 2013		Weighted-average interest rate		Balance as of December 31, 2012		Weighted-average interest rate
U.S. dollar ($)	$ 410,905		1.37%	(b)	$ 410,905		1.66%	(d)
Singapore dollar (SGD)	180,918	(a)	1.40%	(b)	155,098	(c)	1.77%	(d)
British pound sterling (£)	200,216	(a)	1.72%		91,191	(c)	1.94%
Euro (€)	136,743	(a)	1.43%		65,305	(c)	1.56%
Australian dollar (AUD)	92,202	(a)	3.78%		35,340	(c)	4.57%
Total	$ 1,020,984		1.67%	(b)	$ 757,839		1.84%	(d)


	(a)	Based on exchange rates of $0.79 to 1.00 SGD, $1.66 to £1.00, $1.37 to €1.00 and $0.89 to 1.00 AUD, respectively, as of December 31, 2013.
	(b)	As of December 31, 2013, the weighted-average interest rate reflecting interest rate swaps was 1.92% (U.S. dollar), 2.00% (Singapore dollar) and 2.00% (Total). See Note 14 for further discussion on interest rate swaps.
	(c)	Based on exchange rates of $0.82 to 1.00 SGD, $1.63 to £1.00, $1.32 to €1.00 and $1.04 to 1.00 AUD, respectively, as of December 31, 2012.
	(d)	As of December 31, 2012, the weighted-average interest rate reflecting interest rate swaps was 2.17% (U.S. dollar), 2.38% (Singapore dollar) and 2.24% (Total). See Note 14 for further discussion on interest rate swaps.

(5)

The holders of the debentures have the right to require the Operating Partnership to repurchase the debentures in cash in whole or in part for a price of 100% of the principal amount plus accrued and unpaid interest on each of April 15, 2014, April 15, 2019 and April 15, 2024. We have the right to redeem the debentures in cash for a price of 100% of the principal amount plus accrued and unpaid interest commencing on April 18, 2014.


(6)	This amount represents six mortgage loans secured by our interests in 36 NE 2nd Street, 3300 East Birch Street, 100 & 200 Quannapowitt Parkway, 300 Boulevard East, 4849 Alpha Road, and 11830 Webb Chapel Road. Each of these loans is cross-collateralized by the six properties.


(7)	The respective borrower’s assets and credit are not available to satisfy the debts and other obligations of affiliates or any other person.


(8)	The Operating Partnership or its subsidiary provides a limited recourse guarantee with respect to this loan.


(9)	We have entered into interest rate swap agreements as a cash flow hedge for interest generated by these US LIBOR, EURIBOR and GBP LIBOR based loans as well as the U.S. Dollar and Singapore Dollar tranches of the unsecured term loan. See note 14 for further information.


(10)	Based on exchange rate of $1.66 to £1.00 as of December 31, 2013 and $1.63 to £1.00 as of December 31, 2012.


(11)	Based on exchange rate of $1.37 to €1.00 as of December 31, 2013 and $1.32 to €1.00 as of December 31, 2012.


(12)	These loans are also secured by a £7.8 million letter of credit. These loans are cross-collateralized by the two properties.



(13)	These loans were repaid in full in 2013: Clonshaugh Industrial Estate II (June 2013), 1500 Space Park Drive (July 2013), Paul van Vlissingenstraat 16 (July 2013), Chemin de l’Epinglier 2 (July 2013), Mundells Roundabout (October 2013), Gyroscoopweg 2E-2F (October 2013) and 360 Spear Street (November 2013). Net loss from early extinguishment of debt related to write-off of unamortized deferred loan costs and swap breakage fees amounted to $1.8 million for the year ended December 31, 2013.

Global Revolving Credit Facility

On August 15, 2013, the Operating Partnership refinanced its revolving credit facility, which we refer to as the global revolving credit facility, increasing its total borrowing capacity to $2.0 billion from $1.8 billion. The global revolving credit facility has an accordion feature that would enable us to increase the borrowing capacity of the credit facility to $2.55 billion, subject to the receipt of lender commitments and other conditions precedent. The refinanced facility matures on November 3, 2017, with two six-month extension options. The interest rate for borrowings under the expanded facility equals the applicable index plus a margin which is based on the credit rating of our long-term debt and is currently 110 basis points. An annual facility fee on the total commitment amount of the facility, based on the credit rating of our long-term debt and currently 20 basis points, is payable quarterly. Funds may be drawn in U.S., Canadian, Singapore, Australian and Hong Kong dollars, as well as Euro, British pound sterling, Swiss franc, Japanese yen and Mexican peso denominations. As of December 31, 2013, borrowings under the global revolving credit facility bore interest at an overall blended rate of 1.60% comprised of 1.27% (U.S. dollars), 1.33% (Euros), 3.70% (Australian dollars), 1.31% (Hong Kong dollars), 1.21% (Japanese yen) and 2.32% (Canadian dollars). The interest rates are based on 1-month LIBOR, 1-month EURIBOR, 1-month BBR, 1-month HIBOR, 1-month JPY LIBOR and 1-month CDOR, respectively, plus a margin of 1.10%. The facility also bore a base borrowing rate of 3.35% (USD) which is based on U.S. Prime Rate plus a margin of 0.10%. We have used and intend to use available borrowings under the global revolving credit facility to acquire additional properties, fund development opportunities and to provide for working capital and other corporate purposes, including potentially for the repurchase, redemption or retirement of outstanding debt or preferred equity securities. As of December 31, 2013, we have capitalized approximately $17.9 million of financing costs related to the global revolving credit facility. As of December 31, 2013, approximately $724.7 million was drawn under this facility and $20.6 million of letters of credit were issued.

The global revolving credit facility contains various restrictive covenants, including limitations on our ability to incur additional indebtedness, make certain investments or merge with another company, and requirements to maintain financial coverage ratios, including with respect to unencumbered assets. In addition, the global revolving credit facility restricts Digital Realty Trust, Inc. from making distributions to its stockholders, or redeeming or otherwise repurchasing shares of its capital stock, after the occurrence and during the continuance of an event of default, except in limited circumstances including as necessary to enable Digital Realty Trust, Inc. to maintain its qualification as a REIT and to minimize the payment of income or excise tax. As of December 31, 2013, we were in compliance with all of such covenants.

Unsecured Term Loan

On August 15, 2013, we refinanced the senior unsecured multi-currency term loan facility, increasing its total borrowing capacity to $1.0 billion from $750.0 million, and pursuant to the accordion feature total commitments can be increased up to $1.1 billion, subject to the receipt of lender commitments and other conditions precedent. The facility matures on April 16, 2017, with two six-month extension options. Interest rates are based on our senior unsecured debt ratings and are currently 120 basis points over the applicable index for floating rate advances. Funds may be drawn in U.S, Singapore and Australian dollars, as well as Euro and British pound sterling denominations with the option to add Hong Kong dollars and Japanese yen upon an accordion exercise. Based on exchange rates in effect at December 31, 2013, the balance outstanding is approximately $1,021.0 million. We have used borrowings under the term loan for acquisitions, repayment of indebtedness, development, working capital and general corporate purposes. The covenants under this loan are consistent with our global revolving credit facility and, as of December 31, 2013, we were in compliance with all of such covenants. As of December 31, 2013, we have capitalized approximately $8.4 million of financing costs related to the unsecured term loan.

Unsecured Senior Notes

Prudential Shelf Facility

On January 20, 2010, the Operating Partnership closed the sale of $100.0 million aggregate principal amount of its senior unsecured term notes to Prudential Investment Management, Inc. and certain of its affiliates, or, collectively, Prudential, pursuant to a Note Purchase and Private Shelf Agreement, which we refer to as the Prudential shelf facility. The notes were issued in two series referred to as the series D and series E notes. The series D notes have a principal amount of $50.0 million, an interest-only rate of 4.57% per annum and a five-year maturity, and the series E notes have a principal amount of $50.0 million, an interest-only rate of 5.73% per annum and a seven-year maturity. On February 3, 2010, the Operating Partnership closed the sale of an additional $17.0 million aggregate principal amount of its senior unsecured term notes, which we refer to as the series F notes, to Prudential pursuant to the Prudential shelf facility. The series F notes have an interest-only rate of 4.50% per annum and a five-year maturity. We used the proceeds of the series D, series E and series F notes to fund acquisitions, to temporarily repay borrowings under our corporate revolving credit facility, to fund working capital and for general corporate purposes. The sale of the series A ($25.0 million), series B ($33.0 million) and series C ($25.0 million) were completed in July 2008, November 2008 and January 2009, respectively. We may prepay the notes of any series, in whole or in part, at any time at a price equal to the principal amount and accrued interest of the notes being prepaid, plus a make-whole provision. On December 8, 2010, the Operating Partnership and Prudential entered into an amendment to the Note Purchase and Private Shelf Agreement, increasing the capacity of the Prudential shelf facility from $200.0 million to $250.0 million. Our ability to make additional issuances of notes under the Prudential shelf facility expired on July 24, 2011, with $50.0 million remaining unissued under the shelf facility. On July 25, 2011, we repaid the $25.0 million of 7.0% Series A unsecured notes under the Prudential shelf facility at maturity. On November 5, 2013, we repaid the $33.0 million of 9.32% Series B unsecured notes under the Prudential shelf facility at maturity. As of December 31, 2013 and 2012, there was $142.0 million and $175.0 million of unsecured senior notes outstanding, respectively.

On August 15, 2013, concurrent with the refinancing of the global revolving credit facility, the Operating Partnership and Digital Realty Trust, Inc. and the other subsidiary guarantors set forth therein entered into Amendment No.1 to the Amended and Restated Note Purchase and Private Shelf Agreement with Prudential to conform the restrictive and financial covenants of the original Prudential shelf facility that apply to the outstanding Series B, C, D, E and F Notes under the Prudential shelf facility to those in the global revolving credit facility described above and, subject to the completion of specified conditions, to authorize the potential issuance and sale of up to $50.0 million of additional senior unsecured fixed-rate term notes. The Prudential shelf facility contains restrictive covenants that are identical to those in our global revolving credit facility.

Senior Notes

4.500% Notes due 2015

On July 8, 2010, the Operating Partnership issued $375.0 million aggregate principal amount of notes, maturing on July 15, 2015 with an interest rate of 4.50% per annum (the 2015 Notes). The purchase price paid by the initial purchasers was 99.697% of the principal amount. The 2015 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2015 Notes is payable on January 15 and July 15 of each year, beginning on January 15, 2011. The net proceeds from the offering after deducting the original issue discount of approximately $1.1 million and underwriting commissions and expenses of approximately $3.1 million was approximately $370.8 million.

The indenture governing the 2015 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2013, we were in compliance with each of these financial covenants.

We entered into a registration rights agreement whereby the Operating Partnership agreed to conduct an offer to exchange the 2015 Notes for a new series of publicly registered notes with substantially identical terms. If the Operating Partnership did not fulfill certain of its obligations under the registration rights agreement, it would have been required to pay liquidated damages to the holders of the 2015 Notes. No separate contingent obligation was recorded as no liquidated damages became probable. We filed a registration statement with the U.S. Securities and Exchange Commission in October 2010 in connection with the exchange offer, which was declared effective in December 2010. We completed the exchange offer on January 19, 2011.

5.875% Notes due 2020

On January 28, 2010, the Operating Partnership issued $500.0 million aggregate principal amount of notes, maturing on February 1, 2020 with an interest rate of 5.875% per annum (the 2020 Notes). The purchase price paid by the initial purchasers was 98.296% of the principal amount. The 2020 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2020 Notes is payable on February 1 and August 1 of each year, beginning on August 1, 2010. The net proceeds from the offering after deducting the original issue discount of approximately $8.5 million and underwriting commissions and expenses of approximately $4.4 million was approximately $487.1 million. The 2020 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2020 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2013, we were in compliance with each of these financial covenants.

We entered into a registration rights agreement whereby the Operating Partnership agreed to conduct an offer to exchange the 2020 Notes for a new series of publicly registered notes with substantially identical terms. If the Operating Partnership did not fulfill certain of its obligations under the registration rights agreement, it would have been required to pay liquidated damages to the holders of the 2020 Notes. No separate contingent obligation was recorded as no liquidated damages became probable. We filed a registration statement with the U.S. Securities and Exchange Commission in June 2010 in connection with the exchange offer, which was declared effective in September 2010. We completed the exchange offer on November 5, 2010.

5.250% Notes due 2021

On March 8, 2011, the Operating Partnership issued $400.0 million aggregate principal amount of notes, maturing on March 15, 2021 with an interest rate of 5.250% per annum (the 2021 Notes). The purchase price paid by the initial purchasers was 99.775% of the principal amount. The 2021 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2021 Notes is payable on March 15 and September 15 of each year, beginning on September 15, 2011. The net proceeds from the offering after deducting the original issue discount of approximately $0.9 million and underwriting commissions and expenses of approximately $3.6 million was approximately $395.5 million. The 2021 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2021 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2013, we were in compliance with each of these financial covenants.

3.625% Notes due 2022

On September 24, 2012, the Operating Partnership issued $300.0 million in aggregate principal amount of notes, maturing on October 1, 2022 with an interest rate of 3.625% per annum (the 2022 Notes). The purchase price paid by the initial purchasers was 98.684% of the principal amount. The 2022 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2022 Notes is payable on April 1 and October 1 of each year, beginning on April 1, 2013. The net proceeds from the offering after deducting the original issue discount of approximately $3.9 million and underwriting commissions and expenses of approximately $3.0 million was approximately $293.1 million. We used the net proceeds from this offering to temporarily repay borrowings under our global revolving credit facility. The 2022 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2022 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2013, we were in compliance with each of these financial covenants.

4.250% Notes due 2025

On January 18, 2013, Digital Stout Holding, LLC, a wholly-owned subsidiary of the Operating Partnership, issued £400.0 million (or approximately $634.8 million based on the exchange rate of £1.00 to $1.59 on January 18, 2013) aggregate principal amount of its 4.250% Guaranteed Notes due 2025, or the 2025 Notes. The 2025 Notes are senior unsecured obligations of Digital Stout Holding, LLC and are fully and unconditionally guaranteed by the Company and the Operating Partnership. Interest on the 2025 Notes is payable semiannually in arrears at a rate of 4.250% per annum. The net proceeds from the offering after deducting the original issue discount of approximately $4.8 million and underwriting commissions and estimated expenses of approximately $5.8 million was approximately $624.2 million. We used the net proceeds from this offering to temporarily repay borrowings under our global revolving credit facility. The 2025 Notes have been reflected net of discount in the consolidated balance sheet. The indenture governing the 2025 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of the unsecured debt. At December 31, 2013, we were in compliance with all of such covenants.

Exchangeable Senior Debentures

5.50% Exchangeable Senior Debentures due 2029

On April 20, 2009, the Operating Partnership issued $266.4 million of its 5.50% exchangeable senior debentures due April 15, 2029 (the 2029 Debentures). Costs incurred to issue the 2029 Debentures were approximately $7.8 million. These costs are being amortized over a period of five years, which represents the estimated term of the 2029 Debentures, and are included in deferred financing costs, net in the consolidated balance sheet. The 2029 Debentures are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc.

Interest is payable on October 15 and April 15 of each year beginning October 15, 2009 until the maturity date of April 15, 2029. The 2029 Debentures bear interest at 5.50% per annum and may be exchanged for shares of Digital Realty Trust, Inc. common stock at an exchange rate that was initially 23.2558 shares per $1,000 principal amount of 2029 Debentures. The exchange rate on the 2029 Debentures is subject to adjustment for certain events, including, but not limited to, certain dividends on Digital Realty Trust, Inc. common stock in excess of $0.33 per share per quarter (the “reference dividend”). Effective December 11, 2013, the exchange rate has been adjusted to 25.5490 shares per $1,000 principal amount of 2029 Debentures as a result of the aggregate dividends in excess of the reference dividend that Digital Realty Trust, Inc. declared and paid on its common stock beginning with the quarter ended September 30, 2013 and through the quarter ended December 31, 2013. Due to the fact that the exchange feature for the 2029 Debentures must be settled in the common stock of Digital Realty Trust, Inc., accounting guidance on convertible debt instruments that requires the principal amount to be settled in cash upon conversion does not apply.

The table below summarizes our debt maturities and principal payments as of December 31, 2013 (in thousands):


	Global Revolving Credit Facility (1)	Unsecured Term Loan (1)	Prudential Shelf Facility	Senior Notes	Exchangeable Senior Debentures (2)	Mortgage Loans (3)	Total Debt
2014	$ -	$ -	$ -	$ -	$ 266,400	$ 180,464	$ 446,864
2015	-	-	67,000	375,000	-	77,432	519,432
2016	-	-	25,000	-	-	194,023	219,023
2017	724,668	1,020,984	50,000	-	-	110,550	1,906,202
2018	-	-	-	-	-	3,047	3,047
Thereafter	-	-	-	1,862,280	-	17,733	1,880,013
Subtotal	$ 724,668	$ 1,020,984	$ 142,000	$ 2,237,280	$ 266,400	$ 583,249	$ 4,974,581
Unamortized discount	-	-	-	(15,048)	-	-	(15,048)
Unamortized premium	-	-	-	-	-	2,359	2,359
Total	$ 724,668	$ 1,020,984	$ 142,000	$ 2,222,232	$ 266,400	$ 585,608	$ 4,961,892


(1)	Subject to two six-month extension options exercisable by us. The bank group is obligated to grant the extension options provided we give proper notice, we make certain representations and warranties and no default exists under the global revolving credit facility and the unsecured term loan, as applicable.


(2)	Assumes maturity of the 2029 Debentures at their first redemption date in April 2014.


(3)	Our mortgage loans are generally non-recourse to us, subject to carve-outs for specified actions by us or specified undisclosed environmental liabilities. As of December 31, 2013, we provided partial letter of credit support with respect to approximately $37.3 million of the outstanding mortgage indebtedness (based on exchange rates as of December 31, 2013).