Rental revenues for 2022, 2021 and 2020, respectively, are comprised of the following:


	Years ended December 31,
	2022		2021			2020
Base rents	$	23,111,000	$	27,946,000		$	29,419,000
Expense recoveries		7,769,000		9,394,000			8,344,000
Percentage rent		534,000		676,000			1,448,000
Straight-line rents		361,000		(61,000	)		(1,513,000	)
Amortization of intangible lease liabilities, net		896,000		657,000			710,000
Total rents	$	32,671,000	$	38,612,000		$	38,408,000

On January 31, 2020, the Company agreed to a cash payment in consideration for permitting a dark anchor tenant to terminate its lease prior to the contractual expiration at Metro Square. As a result of this termination, revenues for 2020, included approximately $7.1 million of other income.

The Company reviews the collectability of charges under its tenant operating leases on a regular basis, taking into consideration changes in factors such as the tenant’s payment history, the financial condition of the tenant, business conditions in the industry in which the tenant operates and economic conditions in the area where the property is located. The Company’s review of collectability of charges under its operating leases includes any accrued rental revenues related to the straight-line method of reporting rental revenue. The Company identified various tenants where collection was no longer considered probable, and therefore, during the years ended December 31, 2022 and 2021, respectively, $0.6 million and $0.2 million of billed charges, consisting of rent and tenant reimbursements, were unpaid. Based on the Company’s determination to record revenue on a cash basis for these tenants, these amounts were not recorded as revenue.

Annual future base rents due to be received under non-cancelable operating leases in effect at December 31, 2022 are approximately as follows:


2023	$	23,961,000
2024		23,133,000
2025		20,845,000
2026		18,550,000
2027		16,313,000
Thereafter		54,132,000
	$	156,934,000

Total future minimum rents do not include expense recoveries for real estate taxes and operating costs, or percentage rents based upon tenants’ sales volume. Such amounts do not include amortization of intangible lease liabilities.