(1) Effective July 1, 1991, the monthly retirement benefit payable to the retirees and beneficiaries of the Arkansas State Highway Employees' Retirement System who are entitled to receive an annuity for July 1991 shall be increased by four percent (4%) above the annuity such retiree or beneficiary received for June 1991.
(2) The increase in benefits as provided in this section shall be added to the base annuity for the purpose of computing the annual postretirement increase as provided in § 24-5-119(a) for the benefit redetermination July 1, 1991, and for all years thereafter.