To compute for each quarter the amount of Commonwealth funds expended by the department for the administration of the food stamp program for every county, and for each city of the first class. For the fiscal year 1965-1966, thirty percent; for the fiscal year 1966-1967, forty percent; and, for the fiscal years 1967-1968, through 1974-1975 and the nine month period ending March 31, 1976, fifty percent of the amount so expended for every county, and for each city of the first class shall be certified to it, and shall become its obligation to be paid to the department.
62 P.S. § 471