We lease commercial space to the U.S. Government through the GSA or other federal agencies or nongovernmental tenants. These leases may contain extension options that are predominately at the sole discretion of the tenant. Certain of our leases contain a “soft-term” period of the lease, meaning that the U.S. Government tenant agency has the right to terminate the lease prior to its stated lease end date. While certain of our leases are contractually subject to early termination, we do not believe that our tenant agencies are likely to terminate these leases early given the build-to-suit features at the properties subject to the leases, the weighted average age of these properties based on the date the property was built or renovated-to-suit, where applicable (approximately 18.9 years as of March 31, 2023), the mission-critical focus of the properties subject to the leases and the current level of operations at such properties. Certain lease agreements include variable lease payments that, in the future, will vary based on changes in inflationary measures, real estate tax rates, usage, or share of expenditures of the leased premises.

The following table summarizes the maturity of fixed lease payments under our leases as of March 31, 2023 (amounts in thousands):


	Payments due by period
	Total		2023 (1)		2024		2025		2026		2027		Thereafter
Fixed lease payments	$	1,965,728		159,517		200,215		189,222		182,419		170,914		1,063,441

(1)

Represents the nine months ending December 31, 2023.

The table below sets forth our composition of lease revenue recognized between fixed and variable components (amounts in thousands):


	For the three months ended March 31,
	2023		2022
Fixed	$	62,924	$	65,447
Variable		5,224		4,992
Rental income		68,148		70,439

We lease corporate office space under operating lease arrangements in Washington, D.C. and San Diego, CA. The leases include variable lease payments that, in the future, will vary based on changes in real estate tax rates, usage, or share of expenditures of the leased premises. We have elected not to separate lease and non-lease components for our corporate office leases.

As of March 31, 2023, the unamortized balances associated with our right-of-use operating lease asset and operating lease liability were $3.4 million and $3.4 million, respectively. We used our incremental borrowing rate, which was arrived at utilizing prevailing market rates and the spread on our revolving credit facility, in order to determine the net present value of the minimum lease payments.

The following table provides quantitative information for our commenced operating leases for the three months ended March 31, 2023 and 2022 (amounts in thousands):


	For the three months ended March 31,
	2023		2022
Cash flows from operating lease costs	$	131	$	101

In addition, the maturity of fixed lease payments under our commenced corporate office leases as of March 31, 2023 is summarized in the table below (amounts in thousands):


Corporate office leases	Payments due by period
2023 (1)		455
2024		768
2025		793
2026		661
2027		368
Thereafter		718
Total future minimum lease payments	$	3,763
Imputed interest		(396	)
Total	$	3,367

(1)

Represents the nine months ended December 31, 2023.