Occupancy by persons or families of low income. "Occupancy by persons or families of low income" shall mean occupancy by persons or families paying rentals or carrying charges not in excess of the average rentals or carrying charges prevailing in local projects of municipally-aided limited-profit housing companies aided under Article II of the Private Housing Finance Law of the State of New York, the occupancy of which commenced on or after May 18, 1970. The rental or carrying charge for any such projects assisted under § 236 of the United States Housing Act of 1937 shall mean the fair market rental or carrying charge determined from time to time in accordance with the provisions of the agreement with the housing company pursuant to said section. Notwithstanding the foregoing, "occupancy by persons or families of low income" in single room occupancy housing shall mean occupancy by persons paying rentals not in excess of seventy-five (75) percent of the Moderate Rehabilitation Fair Market Rents for 0-bedroom units. "Moderate Rehabilitation Fair Market Rent" shall mean one hundred twenty (120) percent of the amount, less tenant utility allowance where applicable, which is indicated for 0-bedroom units on the then current Existing Housing Fair Market Rent Schedule for the § 8 Existing Housing Assistance Payments Program under the administration of the Department. Where the Department determines on the basis of a market survey or other acceptable and documented evidence that the market rents for dwelling units in the immediate neighborhood where the building is located exceeds the applicable Existing Housing Fair Market Rents, the Department may increase said rents by an amount not to exceed ten (10%) percent.