Commencing October 1, 1996, each person, except those whose employer participated in the Employees' Retirement System pursuant to Sections 36-27-6, 36-27-7, and 36-27-7.1, whose effective date of retirement for purposes of receiving benefits from the Employees' Retirement System is prior to October 1, 1996, and who is receiving or is entitled to receive a monthly allowance from the Employees' Retirement System, and certain beneficiaries of deceased members and deceased retirees currently receiving survivor benefits, if the effective date of retirement or death for the deceased retiree or deceased member was prior to October 1, 1996, for purposes of receiving benefits from the Employees' Retirement System shall receive a cost-of-living increase of not less than twenty-five dollars ($25) per month and the increase shall be more if determined as follows:
Ala. Code § 36-27-130 (1975)