CONCENTRATIONS

Tenant Revenue Concentrations—Rental revenue, excluding tenant reimbursements of certain costs, from the U.S. General Services Administration and other government agencies (collectively, "Governmental Tenants"), which primarily occupy properties located in Washington, D.C., accounted for approximately 19.0% and 21.2% of our rental and other property income and hotel income for the three months ended June 30, 2018 and 2017, respectively, and 19.3% and 20.2% for the six months ended June 30, 2018 and 2017, respectively. At June 30, 2018 and December 31, 2017, $4,055,000 and $5,130,000, respectively, was due from Governmental Tenants (Note 16).

Rental revenue, excluding tenant reimbursements of certain costs, from Kaiser Foundation Health Plan, Incorporated ("Kaiser"), which occupies space in two of our Oakland, California properties, accounted for approximately 9.8% and 7.9% of our rental and other property income and hotel income for the three months ended June 30, 2018 and 2017, respectively, and 10.0% and 7.5% for the six months ended June 30, 2018 and 2017, respectively. At June 30, 2018 and December 31, 2017, $195,000 and $91,000, respectively, was due from Kaiser.

Geographical Concentrations of Investments in Real Estate—As of June 30, 2018 and December 31, 2017, we owned 16 and 15 office properties, respectively, one hotel property, two parking garages, and two development sites, one of which is being used as a parking lot. These properties are located in two states and Washington, D.C.

Our revenue concentrations from properties are as follows:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
California	77.7	%	61.1	%	77.2	%	62.2	%
Washington, D.C.	19.1		23.7		19.5		22.2
Texas	3.2		8.0		3.3		7.9
North Carolina	—		4.9		—		5.6
New York	—		2.3		—		2.1
	100.0	%	100.0	%	100.0	%	100.0	%

Our real estate investments concentrations from properties are as follows:



	June 30, 2018		December 31, 2017
California	70.6	%	66.4	%
Washington, D.C.	27.2		31.2
Texas	2.2		2.4
	100.0	%	100.0	%