We lease 451 sites from third parties under certain non-cancelable operating leases that expire from time to time through 2041. The weighted-average remaining lease term was 5.0 years as of December 31, 2022.

Lease expense was classified in the consolidated statements of income as follows (in thousands):


	Year Ended December 31,
	2022		2021		2020
Cost of sales	$	23,457	$	23,765	$	25,214
Operating expenses		15,254		13,531		9,067
General and administrative expenses		931		1,331		1,081
Total	$	39,642	$	38,627	$	35,362

Variable lease payments based on inflation or fuel volume included in the table above totaled $4.4 million, $4.2 million and $3.8 million for 2022, 2021 and 2020, respectively. Short-term lease payments included in the table above that are excluded from the lease liability amounted to $0.2 million, $0.1 million and $0.8 million for 2022, 2021 and 2020, respectively. Cash paid for amounts included in the measurement of lease liabilities under operating leases totaled $35.0 million, $34.3 million and $30.8 million for 2022, 2021 and 2020, respectively.

As of December 31, 2022, future minimum rental payments under operating leases, excluding variable lease payments or short-term payments, were as follows (in thousands). The weighted-average discount rate as of December 31, 2022 and 2021 was 6.0% and 6.2%, respectively.


2023		36,548
2024		33,686
2025		31,559
2026		28,537
2027		22,780
Thereafter		78,985
Total future payments		232,095
Less impact of discounting		61,530
		170,565
Current portion		35,345
Long-term portion	$	135,220

Most lease agreements include provisions for renewals. We generally do not include renewal options in our lease term for purposes of measuring our lease liabilities and right-of-use assets unless the sublease to our customer extends beyond the term of the head lease.

Of our leased sites, we operate 123 of them as company operated sites. Substantially all the remaining leased sites are subleased to lessee dealers or commission agents under leases with terms generally ranging from one to ten years and which may include renewal options. Sublease rental income amounted to $35.4 million, $34.5 million and $34.8 million for 2022, 2021 and 2020, respectively.

Motor fuel stations are leased to tenants under operating leases with various expiration dates ranging through 2037. Most lease agreements include provisions for renewals. We generally do not include renewal options in our lease term. Future minimum rental payments under non-cancelable operating leases with third parties as of December 31, 2022 were as follows (in thousands):


2023		47,675
2024		41,697
2025		32,815
2026		22,578
2027		14,534
Thereafter		22,865
Total future minimum lease payments	$	182,164

The future minimum rental payments presented above do not include contingent rent based on future inflation, future revenues or volumes of the lessee, or non-lease components for amounts that may be received as tenant reimbursements for certain operating costs.

Deferred rent income from straight-line rent relates to the cumulative amount by which straight-line rental income recorded to date exceeds cash rents billed to date under the lease agreement and totaled $5.1 million at both December 31, 2022 and 2021.