

					Initial Cost to Company									Cost Amount Carried at Close of Period
Property	City	State	Encumbrances(1)		Land		Buildings and Improvements		Costs Capitalized Subsequent to Acquisition, Net		Impairment/Write Downs			Land		Buildings and Improvements		Total(2)		Accumulated Depreciation(3)		Date Acquired	Original Construction Date
1225 Seventeenth Street	Denver	CO	$	—	$	22,400	$	110,090	$	28,273	$	(1,563	)	$	22,400	$	136,800	$	159,200	$	31,093	6/24/2009	1982
5073, 5075, & 5085 S. Syracuse Street	Denver	CO	—		4,720		58,890		—		—			4,720		58,890		63,610		11,287		4/16/2010	2007
1601 Dry Creek Drive	Longmont	CO	—		3,714		24,397		7,498		(156		)	3,714		31,739		35,453		10,751		10/26/2004	1982
97 Newberry Road	East Windsor	CT	5,404		2,960		12,360		30		—			2,943		12,407		15,350		3,485		10/24/2006	1989
1250 H Street, NW	Washington	DC	—		5,975		53,778		14,906		(248		)	5,975		68,436		74,411		30,990		6/23/1998	1992
Georgetown-Green and Harris Buildings	Washington	DC	—		24,000		35,979		44		—			24,000		36,023		60,023		7,501		9/3/2009	1960;1975
600 West Chicago Avenue	Chicago	IL	—		34,980		315,643		50,761		(322		)	34,980		366,082		401,062		57,951		8/10/2011	1908
8750 Bryn Mawr Avenue	Chicago	IL	—		6,600		77,764		14,234		(258		)	6,600		91,740		98,340		17,342		10/28/2010	1985
109 Brookline Avenue	Boston	MA	—		3,168		30,397		15,233		(1,397		)	3,168		44,233		47,401		20,494		9/28/1995	1915
777 East Eisenhower Parkway	Ann Arbor	MI	—		3,675		26,988		4,485		—			3,675		31,473		35,148		5,821		6/15/2010	1975;2006
1735 Market Street	Philadelphia	PA	—		24,753		222,775		81,484		(14,927		)	24,748		289,337		314,085		125,376		6/30/1998	1990
206 East 9th Street	Austin	TX	26,536		7,900		38,533		4,058		(12		)	7,900		42,579		50,479		6,169		5/31/2012	1984
Bridgepoint Square	Austin	TX	—		7,784		70,526		17,125		(770		)	7,784		86,881		94,665		42,573		12/5/1997	1986;1996;1997
Research Park	Austin	TX	—		15,859		60,175		17,439		—			21,213		72,260		93,473		34,941		10/7/1998; 10/11/2016	1968;1998; 2001
333 108th Avenue NE	Bellevue	WA	—		14,400		136,412		2,781		(31		)	14,400		139,162		153,562		29,467		11/12/2009	2008
600 108th Avenue NE	Bellevue	WA	—		3,555		30,244		18,407		(857		)	3,555		47,794		51,349		15,477		7/16/2004	1980
			$	31,940	$	186,443	$	1,304,951	$	276,758	$	(20,541	)	$	191,775	$	1,555,836	$	1,747,611	$	450,718

Analysis of the carrying amount of real estate properties and accumulated depreciation:



	Real Estate Properties			Accumulated Depreciation
Balance at January 1, 2015	$	5,728,443		$	1,030,445
Additions(4)	68,118			144,844
Loss on asset impairment	(17,162		)	—
Disposals	(1,892,047		)	(276,350		)
Balance at December 31, 2015	3,887,352			898,939
Additions	113,258			101,647
Loss on asset impairment	(58,595		)	(119		)
Disposals	(1,085,125		)	(245,212		)
Balance at December 31, 2016	2,856,890			755,255
Additions	55,041			71,979
Loss on asset impairment	(6,711		)	—
Properties classified to held for sale	(138,130		)	(62,064		)
Disposals	(1,019,479		)	(314,452		)
Balance at December 31, 2017	$	1,747,611		$	450,718


(1)	Excludes net unamortized premiums and net unamortized deferred financing costs.


(2)	Excludes value of real estate intangibles. Aggregate cost for federal income tax purposes is approximately $1,907,759.


(3)	Depreciation is calculated using the straight line method over estimated useful lives of up to 40 years for buildings and improvements and up to 12 years for personal property.


(4)	Includes adjustments related to changes in foreign currency exchange rates for real estate properties additions of $0, $0 and $(13,217), and adjustments to accumulated depreciation additions of $0, $0 and $(887), during 2017, 2016 and 2015, respectively.