In order to provide an additional incentive to lenders to broaden their participation in the program and better to assure lenders of receiving a competitive yield on educational loans made under this part, the corporation is authorized to pay to lenders, other than lenders who are schools, a loan discount fee to offset partially initial costs incurred by lenders in interviewing borrowers and in processing borrower applications for loan guaranty. The loan discount payment authorized by this Code section shall be equal to a percentage of the amount of guaranteed loan principal disbursed to a borrower, to be determined and fixed by the corporation; provided, however, that the amount of the loan discount payment shall not exceed 2 percent of the amount of guaranteed loan principal disbursed to the borrower; and provided, further, that the corporation shall not make a commitment to lenders to make loan discount payments under this Code section unless the state has appropriated funds for use by the corporation for the purposes of this Code section and that such appropriated funds plus funds then in and projected to become available to the corporation's state interest subsidy and loan discount fund are deemed to be sufficient to enable the corporation to meet its state interest subsidy and loan discount payment obligations to become due and payable during the period of any fiscal year for which the General Assembly has already enacted an appropriations Act.