The moneys appropriated by R.S. 17:721 shall be used:
The benefit for any person approved by the board of trustees of the teachers' retirement system for old age assistance under the above requirements shall be computed as follows:
One sixtieth of the average salary received for the last five years of active service multiplied by the number of years of accredited service, provided that the total annual payment granted by this Part shall not exceed the average of the annual salary for the last five years of service, and in no case shall it exceed twelve hundred dollars per annum.
The benefits for any person approved by the board of trustees of the teachers' retirement system under Sub-section 2 of this Section, shall be computed in the same manner as above set forth for the computation of the benefit provided by Sub-section 1 of this Section.
La. Consolidated Public Retirement § 11:901.19