The general assembly shall annually appropriate those sums that it may deem necessary to carry out the purposes of § 16-7-35 to § 16-7-47, and the state controller is authorized and directed to draw his or her orders upon the general treasurer for the payment of the sum, or so much of it as may be required from time to time, upon the receipt by the controller of properly authenticated vouchers. In the event that the full amount of housing aid has not been appropriated in a particular fiscal year, school housing aid will not be ratably reduced. In such cases, aid computed for school housing costs for debt service which has been paid by the local community prior to project completion will be deferred. Such aid will be paid within three (3) equal installments beginning the fiscal year after project completion. This deferral provision shall only be applicable if the computed aid for debt service paid by the local community prior to project completion exceeds five hundred thousand dollars ($500,000).