Schedule III - Real Estate and Accumulated Depreciation

12 Months Ended

Dec. 31, 2021

SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]

Schedule III-Real Estate and Accumulated Depreciation

				Initial Cost						Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)		Land		Building and Land Improvements		Costs Capitalized Subsequent to Acquisition		Land		Building and Land Improvements		Total (3)		Accumulated Depreciation (4)		Year Built or Renovated	Date Acquired (5)
100 Light Street (O)	Baltimore, MD	$	—	$	26,715	$	58,002	$	36,662	$	26,715	$	94,664	$	121,379	$	(25,616)	1973/2011	8/7/2015
100 Secured Gateway (O)	Huntsville, AL	—		—		71,089		—		—		71,089		71,089		(2,340)		2020	3/23/2010
1000 Redstone Gateway (O)	Huntsville, AL	9,281		—		20,533		76		—		20,609		20,609		(4,525)		2013	3/23/2010
1100 Redstone Gateway (O)	Huntsville, AL	9,913		—		19,593		88		—		19,681		19,681		(3,912)		2014	3/23/2010
114 National Business Parkway (O)	Annapolis Junction, MD	—		364		3,109		404		364		3,513		3,877		(1,679)		2002	6/30/2000
1200 Redstone Gateway (O)	Huntsville, AL	11,441		—		22,389		141		—		22,530		22,530		(4,509)		2013	3/23/2010
1201 M Street SE (O)	Washington, DC	—		—		49,775		10,290		—		60,065		60,065		(21,051)		2001	9/28/2010
1201 Winterson Road (O)	Linthicum, MD	—		2,130		17,009		901		2,130		17,910		20,040		(5,952)		1985/2017	4/30/1998
1220 12th Street SE (O)	Washington, DC	—		—		42,464		9,749		—		52,213		52,213		(19,797)		2003	9/28/2010
1243 Winterson Road (L)	Linthicum, MD	—		630		—		—		630		—		630		—		(6)	12/19/2001
131 National Business Parkway (O)	Annapolis Junction, MD	—		1,906		7,623		5,893		1,906		13,516		15,422		(7,872)		1990	9/28/1998
132 National Business Parkway (O)	Annapolis Junction, MD	—		2,917		12,259		4,876		2,917		17,135		20,052		(11,075)		2000	5/28/1999
133 National Business Parkway (O)	Annapolis Junction, MD	—		2,517		10,068		6,731		2,517		16,799		19,316		(10,935)		1997	9/28/1998
134 National Business Parkway (O)	Annapolis Junction, MD	—		3,684		7,517		5,726		3,684		13,243		16,927		(8,014)		1999	11/13/1998
1340 Ashton Road (O)	Hanover, MD	—		905		3,620		2,540		905		6,160		7,065		(3,423)		1989	4/28/1999
13450 Sunrise Valley Drive (O)	Herndon, VA	—		1,386		5,576		4,952		1,386		10,528		11,914		(6,583)		1998	7/25/2003
13454 Sunrise Valley Drive (O)	Herndon, VA	—		2,847		11,986		9,240		2,847		21,226		24,073		(12,918)		1998	7/25/2003
135 National Business Parkway (O)	Annapolis Junction, MD	—		2,484		9,750		7,003		2,484		16,753		19,237		(10,779)		1998	12/30/1998
1362 Mellon Road (O)	Hanover, MD	—		950		3,864		1,632		950		5,496		6,446		(1,193)		2006	2/10/2006
13857 McLearen Road (O)	Herndon, VA	—		3,507		30,177		4,915		3,507		35,092		38,599		(13,842)		2007	7/11/2012
140 National Business Parkway (O)	Annapolis Junction, MD	—		3,407		24,167		1,784		3,407		25,951		29,358		(11,646)		2003	12/31/2003
141 National Business Parkway (O)	Annapolis Junction, MD	—		2,398		9,538		4,832		2,398		14,370		16,768		(9,758)		1990	9/28/1998
14280 Park Meadow Drive (O)	Chantilly, VA	—		3,731		15,953		5,500		3,731		21,453		25,184		(10,469)		1999	9/29/2004
1460 Dorsey Road (L)	Hanover, MD	—		1,577		115		—		1,577		115		1,692		—		(6)	2/28/2006
14840 Conference Center Drive (O)	Chantilly, VA	—		1,572		8,175		5,730		1,572		13,905		15,477		(7,895)		2000	7/25/2003
14850 Conference Center Drive (O)	Chantilly, VA	—		1,615		8,358		5,345		1,615		13,703		15,318		(7,455)		2000	7/25/2003
14900 Conference Center Drive (O)	Chantilly, VA	—		3,436		14,402		9,282		3,436		23,684		27,120		(14,024)		1999	7/25/2003
1501 South Clinton Street (O)	Baltimore, MD	—		27,964		51,990		23,731		27,964		75,721		103,685		(31,475)		2006	10/27/2009
15049 Conference Center Drive (O)	Chantilly, VA	—		4,415		20,365		17,846		4,415		38,211		42,626		(20,360)		1997	8/14/2002
15059 Conference Center Drive (O)	Chantilly, VA	—		5,753		13,615		4,543		5,753		18,158		23,911		(10,774)		2000	8/14/2002
1550 West Nursery Road (O)	Linthicum, MD	—		14,071		16,930		—		14,071		16,930		31,001		(6,678)		2009	10/28/2009
1560 West Nursery Road (O)	Linthicum, MD	—		1,441		113		—		1,441		113		1,554		(22)		2014	10/28/2009
1610 West Nursery Road (O)	Linthicum, MD	—		259		246		—		259		246		505		(29)		2016	4/30/1998
1616 West Nursery Road (O)	Linthicum, MD	—		393		3,323		75		393		3,398		3,791		(358)		2017	4/30/1998
1622 West Nursery Road (O)	Linthicum, MD	—		393		2,542		—		393		2,542		2,935		(308)		2016	4/30/1998
16442 Commerce Drive (O)	Dahlgren, VA	—		613		2,582		1,135		613		3,717		4,330		(1,988)		2002	12/21/2004
16480 Commerce Drive (O)	Dahlgren, VA	—		1,856		7,425		2,619		1,856		10,044		11,900		(4,754)		2000	12/28/2004

			Initial Cost			Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)	Land	Building and Land Improvements	Costs Capitalized Subsequent to Acquisition	Land	Building and Land Improvements	Total (3)	Accumulated Depreciation (4)	Year Built or Renovated	Date Acquired (5)
16501 Commerce Drive (O)	Dahlgren, VA	—	522	2,090	1,040	522	3,130	3,652	(1,544)	2002	12/21/2004
16539 Commerce Drive (O)	Dahlgren, VA	—	688	2,860	2,326	688	5,186	5,874	(3,058)	1990	12/21/2004
16541 Commerce Drive (O)	Dahlgren, VA	—	773	3,094	2,596	773	5,690	6,463	(2,989)	1996	12/21/2004
16543 Commerce Drive (O)	Dahlgren, VA	—	436	1,742	838	436	2,580	3,016	(1,348)	2002	12/21/2004
1751 Pinnacle Drive (O)	McLean, VA	—	10,486	42,339	33,825	10,486	76,164	86,650	(42,720)	1989/1995	9/23/2004
1753 Pinnacle Drive (O)	McLean, VA	—	8,275	34,353	24,092	8,275	58,445	66,720	(28,325)	1976/2004	9/23/2004
206 Research Boulevard (O)	Aberdeen, MD	—	—	—	—	—	—	—	—	2012	9/14/2007
209 Research Boulevard (O)	Aberdeen, MD	—	134	1,711	543	134	2,254	2,388	(687)	2010	9/14/2007
210 Research Boulevard (O)	Aberdeen, MD	—	113	1,402	426	113	1,828	1,941	(543)	2010	9/14/2007
2100 L Street (O)	Washington, DC	—	57,385	94,152	—	57,385	94,152	151,537	(1,987)	2020	8/11/2015
2100 Rideout Road (O)	Huntsville, AL	—	—	7,336	2,995	—	10,331	10,331	(2,274)	2016	3/23/2010
22289 Exploration Drive (O)	Lexington Park, MD	—	1,422	5,719	2,129	1,422	7,848	9,270	(4,369)	2000	3/24/2004
22299 Exploration Drive (O)	Lexington Park, MD	—	1,362	5,791	3,049	1,362	8,840	10,202	(5,297)	1998	3/24/2004
22300 Exploration Drive (O)	Lexington Park, MD	—	1,094	5,038	2,770	1,094	7,808	8,902	(4,134)	1997	11/9/2004
22309 Exploration Drive (O)	Lexington Park, MD	—	2,243	10,419	8,114	2,243	18,533	20,776	(8,947)	1984/1997	3/24/2004
23535 Cottonwood Parkway (O)	California, MD	—	692	3,051	648	692	3,699	4,391	(2,193)	1984	3/24/2004
250 W Pratt St (O)	Baltimore, MD	—	8,057	34,588	18,482	8,057	53,070	61,127	(18,418)	1985	3/19/2015
2600 Park Tower Drive (O)	Vienna, VA	—	20,284	34,443	4,621	20,284	39,064	59,348	(8,392)	1999	4/15/2015
2691 Technology Drive (O)	Annapolis Junction, MD	—	2,098	17,334	5,565	2,098	22,899	24,997	(12,224)	2005	5/26/2000
2701 Technology Drive (O)	Annapolis Junction, MD	—	1,737	15,266	7,033	1,737	22,299	24,036	(13,380)	2001	5/26/2000
2711 Technology Drive (O)	Annapolis Junction, MD	—	2,251	21,611	4,335	2,251	25,946	28,197	(14,988)	2002	11/13/2000
2720 Technology Drive (O)	Annapolis Junction, MD	—	3,863	29,272	2,897	3,863	32,169	36,032	(14,204)	2004	1/31/2002
2721 Technology Drive (O)	Annapolis Junction, MD	—	4,611	14,597	3,783	4,611	18,380	22,991	(10,792)	2000	10/21/1999
2730 Hercules Road (O)	Annapolis Junction, MD	—	8,737	31,612	8,998	8,737	40,610	49,347	(23,935)	1990	9/28/1998
30 Light Street (O)	Baltimore, MD	—	—	12,101	1,008	—	13,109	13,109	(2,308)	2009	8/7/2015
300 Secured Gateway (O)	Annapolis Junction, MD	—	—	3,128	—	—	3,128	3,128	—	(7)	3/23/2010
300 Sentinel Drive (O)	Annapolis Junction, MD	—	1,517	59,165	2,569	1,517	61,734	63,251	(18,370)	2009	11/14/2003
302 Sentinel Drive (O)	Annapolis Junction, MD	—	2,648	29,687	2,293	2,648	31,980	34,628	(10,987)	2007	11/14/2003
304 Sentinel Drive (O)	Annapolis Junction, MD	—	3,411	24,917	4,875	3,411	29,792	33,203	(12,067)	2005	11/14/2003
306 Sentinel Drive (O)	Annapolis Junction, MD	—	3,260	22,592	3,303	3,260	25,895	29,155	(10,098)	2006	11/14/2003
308 Sentinel Drive (O)	Annapolis Junction, MD	—	1,422	26,208	2,354	1,422	28,562	29,984	(7,882)	2010	11/14/2003
310 Sentinel Way (O)	Annapolis Junction, MD	—	2,372	42,591	—	2,372	42,591	44,963	(6,103)	2016	11/14/2003
310 The Bridge Street (O)	Huntsville, AL	—	261	26,530	5,227	261	31,757	32,018	(12,236)	2009	8/9/2011
312 Sentinel Way (O)	Annapolis Junction, MD	—	3,138	27,797	—	3,138	27,797	30,935	(5,084)	2014	11/14/2003
314 Sentinel Way (O)	Annapolis Junction, MD	—	1,254	7,741	—	1,254	7,741	8,995	(1,480)	2008	11/14/2003
316 Sentinel Way (O)	Annapolis Junction, MD	—	2,748	38,156	193	2,748	38,349	41,097	(9,410)	2011	11/14/2003
318 Sentinel Way (O)	Annapolis Junction, MD	—	2,185	28,426	560	2,185	28,986	31,171	(11,482)	2005	11/14/2003

			Initial Cost			Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)	Land	Building and Land Improvements	Costs Capitalized Subsequent to Acquisition	Land	Building and Land Improvements	Total (3)	Accumulated Depreciation (4)	Year Built or Renovated	Date Acquired (5)
320 Sentinel Way (O)	Annapolis Junction, MD	—	2,067	21,623	127	2,067	21,750	23,817	(7,606)	2007	11/14/2003
322 Sentinel Way (O)	Annapolis Junction, MD	—	2,605	22,827	1,910	2,605	24,737	27,342	(9,329)	2006	11/14/2003
324 Sentinel Way (O)	Annapolis Junction, MD	—	1,656	23,018	6	1,656	23,024	24,680	(6,531)	2010	6/29/2006
4000 Market Street (O)	Huntsville, AL	6,052	—	9,187	—	—	9,187	9,187	(626)	2018	3/23/2010
410 National Business Parkway (O)	Annapolis Junction, MD	—	1,831	23,257	2,259	1,831	25,516	27,347	(6,032)	2012	6/29/2006
4100 Market Street (O)	Huntsville, AL	5,269	—	8,020	7	—	8,027	8,027	(506)	2019	3/23/2010
420 National Business Parkway (O)	Annapolis Junction, MD	—	2,370	29,534	148	2,370	29,682	32,052	(5,467)	2013	6/29/2006
430 National Business Parkway (O)	Annapolis Junction, MD	—	1,852	21,563	1,893	1,852	23,456	25,308	(5,746)	2011	6/29/2006
44408 Pecan Court (O)	California, MD	—	817	1,583	1,751	817	3,334	4,151	(1,983)	1986	3/24/2004
44414 Pecan Court (O)	California, MD	—	405	1,619	1,138	405	2,757	3,162	(1,686)	1986	3/24/2004
44417 Pecan Court (O)	California, MD	—	434	3,822	180	434	4,002	4,436	(2,195)	1989/2015	3/24/2004
44420 Pecan Court (O)	California, MD	—	344	890	291	344	1,181	1,525	(607)	1989	11/9/2004
44425 Pecan Court (O)	California, MD	—	1,309	3,506	2,394	1,309	5,900	7,209	(3,757)	1997	5/5/2004
45310 Abell House Lane (O)	California, MD	—	2,272	13,808	878	2,272	14,686	16,958	(3,888)	2011	8/30/2010
4600 River Road (O)	College Park, MD	—	—	24,032	—	—	24,032	24,032	(436)	2020	1/29/2008
46579 Expedition Drive (O)	Lexington Park, MD	—	1,406	5,796	2,874	1,406	8,670	10,076	(4,563)	2002	3/24/2004
46591 Expedition Drive (O)	Lexington Park, MD	—	1,200	7,199	3,408	1,200	10,607	11,807	(4,557)	2005	3/24/2004
4851 Stonecroft Boulevard (O)	Chantilly, VA	—	1,878	11,558	194	1,878	11,752	13,630	(5,001)	2004	8/14/2002
540 National Business Parkway (O)	Annapolis Junction, MD	—	2,035	31,249	41	2,035	31,290	33,325	(3,321)	2017	6/29/2006
5520 Research Park Drive (O)	Catonsville, MD	—	—	20,072	1,757	—	21,829	21,829	(7,078)	2009	4/4/2006
5522 Research Park Drive (O)	Catonsville, MD	—	—	4,550	855	—	5,405	5,405	(1,851)	2007	3/8/2006
560 National Business Parkway (O)	Annapolis Junction, MD	—	2,193	28,973	—	2,193	28,973	31,166	—	(7)	6/29/2006
5801 University Research Court (O)	College Park, MD	11,120	—	17,431	144	—	17,575	17,575	(1,772)	2018	1/29/2008
5825 University Research Court (O)	College Park, MD	19,552	—	22,771	1,678	—	24,449	24,449	(8,014)	2008	1/29/2008
5850 University Research Court (O)	College Park, MD	20,686	—	31,906	894	—	32,800	32,800	(9,746)	2008	1/29/2008
6000 Redstone Gateway (O)	Huntsville, AL	—	—	8,550	—	—	8,550	8,550	(201)	2020	3/23/2010
610 Guardian Way (O)	Annapolis Junction, MD	—	7,636	49,873	—	7,636	49,873	57,509	(276)	2021	6/29/2006
6200 Redstone Gateway (O)	Huntsville, AL	—	—	14,067	—	—	14,067	14,067	—	(7)	3/23/2010
6700 Alexander Bell Drive (O)	Columbia, MD	—	1,755	7,019	9,541	1,755	16,560	18,315	(9,466)	1988	5/14/2001
6708 Alexander Bell Drive (O)	Columbia, MD	—	897	12,693	1,618	897	14,311	15,208	(4,956)	1988/2016	5/14/2001
6711 Columbia Gateway Drive (O)	Columbia, MD	—	2,683	23,239	2,258	2,683	25,497	28,180	(9,995)	2006-2007	9/28/2000
6716 Alexander Bell Drive (O)	Columbia, MD	—	1,242	4,969	4,672	1,242	9,641	10,883	(6,399)	1990	12/31/1998
6721 Columbia Gateway Drive (O)	Columbia, MD	—	1,753	34,090	7,318	1,753	41,408	43,161	(11,406)	2009	9/28/2000
6724 Alexander Bell Drive (O)	Columbia, MD	—	449	5,039	2,492	449	7,531	7,980	(4,042)	2001	5/14/2001
6731 Columbia Gateway Drive (O)	Columbia, MD	—	2,807	19,098	5,689	2,807	24,787	27,594	(14,085)	2002	3/29/2000
6740 Alexander Bell Drive (O)	Columbia, MD	—	1,424	4,209	757	1,424	4,966	6,390	(2,627)	1992	12/31/1998
6741 Columbia Gateway Drive (O)	Columbia, MD	—	675	1,711	176	675	1,887	2,562	(715)	2008	9/28/2000

			Initial Cost			Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)	Land	Building and Land Improvements	Costs Capitalized Subsequent to Acquisition	Land	Building and Land Improvements	Total (3)	Accumulated Depreciation (4)	Year Built or Renovated	Date Acquired (5)
6750 Alexander Bell Drive (O)	Columbia, MD	—	1,263	12,461	5,856	1,263	18,317	19,580	(11,133)	2001	12/31/1998
6760 Alexander Bell Drive (O)	Columbia, MD	—	890	3,561	3,915	890	7,476	8,366	(5,115)	1991	12/31/1998
6940 Columbia Gateway Drive (O)	Columbia, MD	—	3,545	9,916	9,227	3,545	19,143	22,688	(11,631)	1999	11/13/1998
6950 Columbia Gateway Drive (O)	Columbia, MD	—	3,596	28,312	3,223	3,596	31,535	35,131	(12,711)	1998/2019	10/22/1998
7000 Columbia Gateway Drive (O)	Columbia, MD	—	3,131	12,103	8,551	3,131	20,654	23,785	(10,921)	1999	5/31/2002
7000 Redstone Gateway (O)	Huntsville, AL	—	—	897	—	—	897	897	—	(7)	3/23/2010
7005 Columbia Gateway Drive (L)	Columbia, MD	—	3,036	747	—	3,036	747	3,783	—	(6)	6/26/2014
7015 Albert Einstein Drive (O)	Columbia, MD	—	2,058	6,093	3,560	2,058	9,653	11,711	(5,005)	1999	12/1/2005
7061 Columbia Gateway Drive (O)	Columbia, MD	—	729	3,094	2,884	729	5,978	6,707	(3,608)	2000	8/30/2001
7063 Columbia Gateway Drive (O)	Columbia, MD	—	902	3,684	3,470	902	7,154	8,056	(4,721)	2000	8/30/2001
7065 Columbia Gateway Drive (O)	Columbia, MD	—	919	3,763	3,145	919	6,908	7,827	(4,703)	2000	8/30/2001
7067 Columbia Gateway Drive (O)	Columbia, MD	—	1,829	11,823	6,683	1,829	18,506	20,335	(9,409)	2001	8/30/2001
7100 Redstone Gateway (O)	Huntsville, AL	—	—	12,975	—	—	12,975	12,975	(204)	2021	3/23/2010
7125 Columbia Gateway Drive (O)	Columbia, MD	—	20,487	49,844	24,637	20,487	74,481	94,968	(30,038)	1973/1999	6/29/2006
7130 Columbia Gateway Drive (O)	Columbia, MD	—	1,350	4,359	3,029	1,350	7,388	8,738	(4,101)	1989	9/19/2005
7134 Columbia Gateway Drive (O)	Columbia, MD	—	704	4,700	729	704	5,429	6,133	(1,988)	1990/2016	9/19/2005
7138 Columbia Gateway Drive (O)	Columbia, MD	—	1,104	3,518	2,963	1,104	6,481	7,585	(4,286)	1990	9/19/2005
7142 Columbia Gateway Drive (O)	Columbia, MD	—	1,342	7,148	2,771	1,342	9,919	11,261	(4,494)	1994/2018	9/19/2005
7150 Columbia Gateway Drive (O)	Columbia, MD	—	1,032	3,429	1,705	1,032	5,134	6,166	(1,938)	1991	9/19/2005
7150 Riverwood Drive (O)	Columbia, MD	—	1,821	4,388	1,953	1,821	6,341	8,162	(3,162)	2000	1/10/2007
7160 Riverwood Drive (O)	Columbia, MD	—	2,732	7,006	4,609	2,732	11,615	14,347	(5,300)	2000	1/10/2007
7170 Riverwood Drive (O)	Columbia, MD	—	1,283	3,096	2,387	1,283	5,483	6,766	(2,787)	2000	1/10/2007
7175 Riverwood Drive (O)	Columbia, MD	—	1,788	7,269	—	1,788	7,269	9,057	(1,479)	1996/2013	7/27/2005
7200 Redstone Gateway (O)	Huntsville, AL	—	—	8,348	81	—	8,429	8,429	(1,611)	2013	3/23/2010
7200 Riverwood Drive (O)	Columbia, MD	—	4,089	22,630	4,693	4,089	27,323	31,412	(13,365)	1986	10/13/1998
7205 Riverwood Drive (O)	Columbia, MD	—	1,367	21,419	—	1,367	21,419	22,786	(4,523)	2013	7/27/2005
7272 Park Circle Drive (O)	Hanover, MD	—	1,479	6,300	4,609	1,479	10,909	12,388	(5,971)	1991/1996	1/10/2007
7318 Parkway Drive (O)	Hanover, MD	—	972	3,888	1,647	972	5,535	6,507	(3,120)	1984	4/16/1999
7400 Redstone Gateway (O)	Huntsville, AL	—	—	9,223	75	—	9,298	9,298	(1,519)	2015	3/23/2010
7467 Ridge Road (O)	Hanover, MD	—	1,565	3,116	5,997	1,565	9,113	10,678	(4,585)	1990	4/28/1999
7500 Advanced Gateway (O)	Huntsville, AL	—	—	18,663	—	—	18,663	18,663	(734)	2020	3/23/2010
7600 Advanced Gateway (O)	Huntsville, AL	—	—	13,752	—	—	13,752	13,752	(482)	2020	3/23/2010
7740 Milestone Parkway (O)	Hanover, MD	16,432	3,825	34,176	1,254	3,825	35,430	39,255	(10,226)	2009	7/2/2007
7770 Backlick Road (O)	Springfield, VA	—	6,387	78,891	1,528	6,387	80,419	86,806	(17,275)	2012	3/10/2010
7880 Milestone Parkway (O)	Hanover, MD	—	4,857	26,836	1,338	4,857	28,174	33,031	(4,132)	2015	9/17/2013
8000 Rideout Road (O)	Huntsville, AL	—	—	21,667	—	—	21,667	21,667	(53)	2021 (7)	3/23/2010
8200 Rideout Road (O) (8)	Huntsville, AL	—	—	16,890	—	—	16,890	16,890	—	(7)	3/23/2010

			Initial Cost			Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)	Land	Building and Land Improvements	Costs Capitalized Subsequent to Acquisition	Land	Building and Land Improvements	Total (3)	Accumulated Depreciation (4)	Year Built or Renovated	Date Acquired (5)
8300 Rideout Road (O) (8)	Huntsville, AL	—	—	18,301	—	—	18,301	18,301	—	(7)	3/23/2010
8600 Advanced Gateway (O)	Huntsville, AL	—	—	27,298	—	—	27,298	27,298	(711)	2020	3/23/2010
8621 Robert Fulton Drive (O)	Columbia, MD	—	2,317	12,642	6,191	2,317	18,833	21,150	(8,822)	2005-2006	6/10/2005
8661 Robert Fulton Drive (O)	Columbia, MD	—	1,510	3,764	3,302	1,510	7,066	8,576	(3,825)	2002	12/30/2003
8671 Robert Fulton Drive (O)	Columbia, MD	—	1,718	4,280	4,294	1,718	8,574	10,292	(5,066)	2002	12/30/2003
870 Elkridge Landing Road (O)	Linthicum, MD	—	2,003	9,442	10,464	2,003	19,906	21,909	(12,706)	1981	8/3/2001
8800 Redstone Gateway (O)	Huntsville, AL	11,679	—	18,465	—	—	18,465	18,465	(974)	2019	3/23/2010
891 Elkridge Landing Road (O)	Linthicum, MD	—	1,165	4,772	3,844	1,165	8,616	9,781	(5,472)	1984	7/2/2001
901 Elkridge Landing Road (O)	Linthicum, MD	—	1,156	4,437	6,034	1,156	10,471	11,627	(5,115)	1984	7/2/2001
911 Elkridge Landing Road (O)	Linthicum, MD	—	1,215	4,861	3,307	1,215	8,168	9,383	(5,116)	1985	4/30/1998
938 Elkridge Landing Road (O)	Linthicum, MD	—	922	4,748	1,534	922	6,282	7,204	(3,420)	1984	7/2/2001
939 Elkridge Landing Road (O)	Linthicum, MD	—	939	3,756	4,470	939	8,226	9,165	(6,064)	1983	4/30/1998
9651 Hornbaker Road (D) (9)	Manassas, VA	—	6,050	250,407	17,785	6,050	268,192	274,242	(82,385)	2010	9/14/2010
Arundel Preserve (L)	Hanover, MD	—	13,352	9,717	—	13,352	9,717	23,069	—	(6)	7/2/2007
Canton Crossing Land (L)	Baltimore, MD	—	17,285	8,409	227	17,285	8,636	25,921	—	(6)	10/27/2009
Canton Crossing Util Distr Ctr (O)	Baltimore, MD	—	6,100	10,450	1,689	6,100	12,139	18,239	(6,887)	2006	10/27/2009
Columbia Gateway - Southridge (L)	Columbia, MD	—	6,387	3,722	—	6,387	3,722	10,109	—	(6)	9/20/2004
Dahlgren Technology Center (L)	Dahlgren, VA	—	978	178	—	978	178	1,156	—	(6)	3/16/2005
Expedition VII (O)	Lexington Park, MD	—	705	7,208	—	705	7,208	7,913	—	(7)	3/24/2004
IN 1 (O)	Northern Virginia	—	1,815	16,017	—	1,815	16,017	17,832	(1,136)	2019	8/31/2016
IN 2 (O)	Northern Virginia	—	2,627	28,936	—	2,627	28,936	31,563	(1,804)	2019	8/31/2016
M Square Research Park (L)	College Park, MD	—	—	2,417	—	—	2,417	2,417	—	(6)	1/29/2008
MR Land (L)	Northern Virginia	—	9,038	554	—	9,038	554	9,592	—	(6)	11/8/2018
National Business Park North (L)	Annapolis Junction, MD	—	18,232	36,875	—	18,232	36,875	55,107	—	(6)	6/29/2006
North Gate Business Park (L)	Aberdeen, MD	—	1,755	5	—	1,755	5	1,760	—	(6)	9/14/2007
NoVA Office A (O) (8)	Chantilly, VA	—	2,096	46,849	—	2,096	46,849	48,945	(8,096)	2015	7/18/2002
NoVA Office B (O) (8)	Chantilly, VA	—	739	38,376	—	739	38,376	39,115	(4,715)	2016	7/18/2002
NoVA Office C (O) (8)	Chantilly, VA	—	7,751	78,907	—	7,751	78,907	86,658	(477)	2021	7/18/2002
NoVA Office D (O) (8)	Chantilly, VA	—	6,587	40,559	—	6,587	40,559	47,146	(4,466)	2017	7/2/2013
Oak Grove A (O)	Northern Virginia	—	12,866	34,814	—	12,866	34,814	47,680	(1,358)	2020	11/1/2018
Oak Grove B (O)	Northern Virginia	—	12,866	41,083	—	12,866	41,083	53,949	(1,832)	2019	11/1/2018
Oak Grove C (O)	Northern Virginia	—	9,491	64,671	—	9,491	64,671	74,162	—	(7)	11/1/2018
Oak Grove Phase II (L)	Northern Virginia	—	13,992	13,820	—	13,992	13,820	27,812	—	(6)	11/1/2018
Old Annapolis Road (O)	Columbia, MD	—	1,637	5,500	6,755	1,637	12,255	13,892	(5,362)	1974/1985	12/14/2000
P2 A (O)	Northern Virginia	—	16,853	40,132	—	16,853	40,132	56,985	(1,739)	2020	5/2/2019
P2 B (O)	Northern Virginia	—	22,839	36,362	—	22,839	36,362	59,201	(1,194)	2020	5/2/2019
P2 C (O)	Northern Virginia	—	14,869	31,482	—	14,869	31,482	46,351	(828)	2020	5/2/2019

				Initial Cost						Gross Amounts Carried At Close of Period
Property (Type) (1)	Location	Encumbrances (2)		Land		Building and Land Improvements		Costs Capitalized Subsequent to Acquisition		Land		Building and Land Improvements		Total (3)		Accumulated Depreciation (4)		Year Built or Renovated	Date Acquired (5)
Patriot Ridge (L)	Springfield, VA	—		18,517		14,573		—		18,517		14,573		33,090		—		(6)	3/10/2010
Project EL (O)	Confidential-USA	—		7,430		45,226		—		7,430		45,226		52,656		(552)		2021	1/20/2006
Project EX (O) (10)	Confidential-USA	—		13,010		19,097		—		13,010		19,097		32,107		(1,174)		2018	7/16/2008
PS A (O)	Northern Virginia	—		4,078		2,200		—		4,078		2,200		6,278		—		(7)	1/27/2005
PS B (O)	Northern Virginia	—		3,468		1,940		—		3,468		1,940		5,408		—		(7)	1/27/2005
Redstone Gateway (L)	Huntsville, AL	—		—		29,937		—		—		29,937		29,937		—		(6)	3/23/2010
Sentry Gateway - T (O)	San Antonio, TX	—		14,020		38,804		13		14,020		38,817		52,837		(14,443)		1982/2008	3/30/2005
Sentry Gateway - V (O)	San Antonio, TX	—		—		1,066		—		—		1,066		1,066		(348)		2007	3/30/2005
Sentry Gateway - W (O)	San Antonio, TX	—		—		1,884		71		—		1,955		1,955		(599)		2009	3/30/2005
Sentry Gateway - X (O)	San Antonio, TX	—		1,964		21,178		—		1,964		21,178		23,142		(5,905)		2010	1/20/2006
Sentry Gateway - Y (O)	San Antonio, TX	—		1,964		21,298		—		1,964		21,298		23,262		(5,940)		2010	1/20/2006
Sentry Gateway - Z (O)	San Antonio, TX	—		1,964		30,573		—		1,964		30,573		32,537		(5,203)		2015	6/14/2005
SP Manassas (L)	Manassas, VA	—		8,156		300		—		8,156		300		8,456		—		(6)	7/24/2019
Westfields - Park Center (L)	Chantilly, VA	—		8,667		3,155		—		8,667		3,155		11,822		—		(6)	7/2/2013
Other Developments, including    intercompany eliminations (V)	Various	—		—		506		259		—		765		765		(115)		Various	Various
		$	121,425	$	720,485	$	3,635,390	$	603,834	$	720,485	$	4,239,224	$	4,959,709	$	(1,234,908)

(1)A legend for the Property Type follows: (O) = Office or Data Center Shell Property; (L) = Land held or pre-development; (D) = Wholesale Data Center; and (V) = Various.

(2)Excludes our Revolving Credit Facility of $76.0 million, term loan facilities of $299.4 million, unsecured senior notes of $1.8 billion, unsecured notes payable of $753,000, and deferred financing costs, net of premiums, on the remaining loans of $798,000.

(3)The aggregate cost of these assets for Federal income tax purposes was approximately $3.7 billion as of December 31, 2021.

(4)The estimated lives over which depreciation is recognized follow: Building and land improvements: 10-40 years; and tenant improvements: related lease terms.

(5)The acquisition date of multi-parcel properties reflects the date of the earliest parcel acquisition. The acquisition date of properties owned through real estate joint ventures reflects the date of the formation of the joint venture.

(6)Held as of December 31, 2021.

(7)Under development as of December 31, 2021.

(8)The carrying amounts of these properties exclude allocated costs of the garage being constructed to support the properties.

(9)Classified as held for sale as of December 31, 2021.

(10)This property represents land under a long-term contract.

The following table summarizes our changes in cost of properties for the years ended December 31, 2021, 2020 and 2019 (in thousands):

	2021		2020		2019
Beginning balance	$	4,686,802	$	4,348,006	$	4,148,529
Improvements and other additions	342,684		405,940		480,418
Sales (1)	(103,097)		(65,475)		(242,497)
Impairments	—		(1,530)		(329)
Other dispositions	(4,511)		(139)		(340)
Reclassification from (to) right-of-use asset	37,831		—		(37,775)
Ending balance	$	4,959,709	$	4,686,802	$	4,348,006
The following table summarizes our changes in accumulated depreciation for the same time periods (in thousands):
	2021		2020		2019
Beginning balance	$	1,124,253	$	1,007,120	$	897,903
Depreciation expense	130,604		119,377		117,973
Sales (1)	(15,438)		(2,105)		(8,416)
Other dispositions	(4,511)		(139)		(340)
Ending balance	$	1,234,908	$	1,124,253	$	1,007,120

(1)Includes our sale, through a series of transactions, of ownership interests in data center shells through newly-formed unconsolidated real estate joint ventures, as described in Note 4 to our consolidated financial statements.