We lease space to tenants under operating leases. Most of the leases provide for the payment of fixed base rentals payable monthly in advance. Office building leases generally require the tenants to reimburse us for operating costs and real estate taxes above their base year costs. Shopping center leases provide for pass-through to tenants the tenant's share of real estate taxes, insurance and maintenance. Shopping center leases also provide for the payment by the lessee of additional rent based on a percentage of the tenants' sales. As of December 31, 2011, future base rental revenue under non-cancelable operating leases, excluding rents for leases with an original term of less than one year and rents resulting from the exercise of renewal options, is as follows:


(Amounts in thousands)
Year Ending December 31:
2012	$	1,807,885
2013		1,718,403
2014		1,609,279
2015		1,425,804
2016		1,232,154
Thereafter		6,045,584

These amounts do not include percentage rentals based on tenants' sales. These percentage rents approximated $8,482,000, $7,912,000 and $8,394,000, for the years ended December 31, 2011, 2010 and 2009, respectively.

None of our tenants accounted for more than 10% of total revenues in any of the years ended December 31, 2011, 2010 and 2009.

Pursuant to a Master Agreement and Guaranty, dated May 1, 1992, we are due $5,000,000 per annum of additional rent from Stop & Shop which was allocated to certain Bradlees former locations. On December 31, 2002, prior to the expiration of the leases to which the additional rent was allocated, we reallocated this rent to other former Bradlees leases also guaranteed by Stop & Shop. Stop & Shop is contesting our right to reallocate and claims that we are no longer entitled to the additional rent. On November 7, 2011, the Court determined that we have a continuing right to allocate the annual rent to unexpired leases covered by the Master Agreement and Guaranty and directed entry of a judgment in our favor ordering Stop & Shop to pay us the unpaid annual rent (see Note 20 – Commitments and Contingencies – Litigation). As of December 31, 2011, we have a $41,983,000 receivable from Stop and Shop.

We are a tenant under operating leases for certain properties. These leases have terms that expire during the next thirty years. Future minimum lease payments under operating leases at December 31, 2011 are as follows:


(Amounts in thousands)
Year Ending December 31:
2012	$	31,472
2013		31,666
2014		31,945
2015		30,596
2016		26,470
Thereafter		1,037,730

Rent expense was $37,177,000, $36,417,000 and $35,011,000 for the years ended December 31, 2011, 2010 and 2009, respectively.

We are also a lessee under capital leases for real estate. Lease terms generally range from 5-20 years with renewal or purchase options. Capitalized leases are recorded at the present value of future minimum lease payments or the fair market value of the property. Capitalized leases are depreciated on a straight-line basis over the estimated life of the asset or life of the related lease, whichever is shorter. Amortization expense on capital leases is included in “depreciation and amortization” on our consolidated statements of income. As of December 31, 2011, future minimum lease payments under capital leases are as follows:


(Amounts in thousands)
Year Ending December 31:
2012	$	707
2013		706
2014		707
2015		706
2016		707
Thereafter		16,014
Total minimum obligations		19,547
Interest portion		(12,876)
Present value of net minimum payments	$	6,671

At December 31, 2011 and 2010, $6,671,000 and $6,714,000, respectively, representing the present value of net minimum payments are included in “Other Liabilities” on our consolidated balance sheets. At December 31, 2011 and 2010, property leased under capital leases had a total cost of $6,216,000 and $6,216,000, respectively, and accumulated depreciation of $2,184,000 and $2,029,000, respectively.