NOTE 10. RENTAL INCOME

During the nine months ended September 30, 2019, approximately 94% of rental income was related to residential apartments and condominium units with leases of one year or less. The majority of these leases expire in June, July and August. Approximately 6% was related to commercial properties, which have minimum future annual rental income on non-cancellable operating leases at September 30, 2019 as follows:


	Commercial
	Property Leases
2020	$	2,780,000
2021		2,407,000
2022		1,559,000
2023		1,131,000
2024		545,000
Thereafter		683,000
	$	9,105,000

The aggregate minimum future rental income does not include contingent rentals that may be received under various leases in connection with common area charges and real estate taxes. Aggregate contingent rentals from continuing operations were approximately $450,000 and $632,000 for the nine months ended September 30, 2019 and 2018 respectively. Staples and Trader Joes, tenants at Staples Plaza, are approximately 30% of the total commercial rental income.

The following information is provided for commercial leases:


	Annual base				Percentage of
	rent for		Total square feet	Total number of	annual base rent for
Through September 30,	expiring leases		for expiring leases	leases expiring	expiring leases
2020	$	213,099	11,062	12	7	%
2021		887,955	37,817	10	30	%
2022		538,983	17,038	7	18	%
2023		405,072	12,546	6	14	%
2024		747,762	24,903	11	25	%
2025		14,994	308	1	1	%
2026		—	—	—	—	%
2027		—	—	—	—	%
2028		—	—	—	—	%
2029		142,450	3,850	1	5	%
2030		—	—	—	—	%
Totals	$	2,950,315	107,524	48	100	%

Rents receivable are net of an allowance for doubtful accounts of approximately $255,000 and $532,000 at September 30, 2019 and December 31, 2018. Included in rents receivable at September 30, 2019 is approximately $92,000 resulting from recognizing rental income from non-cancelable commercial leases with future rental increases on a straight-line basis. The majority of this amount is for long-term leases at 62 Boylston Street, Cypress Street, and Staples Plaza in Massachusetts.

Rents receivable at September 30, 2019 also includes approximately $92,000 representing the deferral of rental concession primarily related to the residential properties.