(A) Effective July 1, 1981, each person eligible to receive an age and service or disability pension, allowance, or benefit pursuant to Chapter 742. of the Revised Code that was based upon an award made effective before January 1, 1974, shall have the person's monthly pension increased by five per cent, except that the twelve-month sum of such increase shall not exceed five per cent of the first five thousand dollars of the annual pension allowance or benefit. A member of the Ohio police and fire pension fund or a survivor who is receiving a pension or benefit in accordance with the rules in force on April 1, 1947, governing the granting of pensions and benefits, which provide an increase in the original pension or benefit from time to time pursuant to changes in the salaries of active members, shall not be eligible to receive the increase provided by this section.