Certain of the Company’s investments in real estate are subject to a ground lease. The Company’s ground leases are classified as operating leases based on the characteristics of the respective lease. The ground leases were acquired as part of the acquisition of real estate and no incremental costs were incurred for such ground leases. The Company’s ground leases are non-cancelable and do not contain any additional renewal options.

The following table presents the future lease payments due under the Company’s ground leases as of December 31, 2021 ($ in thousands):

Year	Operating Lease
2022	$	686
2023		686
2024		686
2025		712
2026		713
Thereafter		26,497
Total undiscounted future lease payments		29,980
Difference between undiscounted cash flows and discounted cash flows		(17,481	)
Total lease liability	$	12,499

The Company utilized its incremental borrowing rate, which was between 4.5% and 6% to determine its lease liabilities. As of December 31, 2021, the weighted average remaining lease term of the Company’s operating leases were 38 years.

Payments under the Company’s ground leases contain fixed payment components. The Company’s ground leases contained escalations prior to the Company’s hold period.

The Company’s rental revenue primarily consists of rent earned from operating leases at the Company’s multifamily, single-family rental, industrial, office, self-storage, medical office and other properties. Leases at the Company’s industrial, office, medical office and other properties generally include a fixed base rent and certain leases also contain a variable component. The variable component of the Company’s operating leases at its industrial, office, medical office and other properties primarily consist of the reimbursement of operating expenses such as real estate taxes, insurance, and common area maintenance costs.

Leases at the Company’s industrial, office, medical office and other properties are generally longer term and may contain extension and termination options at the lessee’s election. The Company’s rental revenue earned from leases at the Company’s multifamily, single-family rental and self-storage properties primarily consists of a fixed base rent and certain leases contain a variable component that allows for the pass-through of certain operating expenses such as utilities. Leases at the Company’s multifamily, single-family rental and self-storage properties are short term in nature, generally not greater than 12 months in length.

The following table summarizes the fixed and variable components of the Company’s operating leases ($ in thousands):

	For the Year Ended December 31,
	2021		2020		2019
Fixed lease payments	$	530,093	$	238,897	$	46,908
Variable lease payments		74,481		34,950		4,882
Rental revenue	$	604,574	$	273,847	$	51,790

The following table presents the undiscounted future minimum rents the Company expects to receive for its industrial, office, medical office and other properties as of December 31, 2021 ($ in thousands). Leases at the Company’s multifamily, single-family and self-storage properties are short term, generally 12 months or less, and are therefore not included.

Year	Future Minimum Rents
2022	$	229,976
2023		218,831
2024		195,541
2025		169,574
2026		147,597
Thereafter		525,167
Total	$	1,486,686