1 3/4% of his annual salary during the time between the day before the effective date and the date he attained age 65, for such service, with interest thereon at the effective rate to age 65, upon the assumption that 1/12 of such 1 3/4% of such annual salary was due on the last day of each month of such service.
1 3/4% of annual salary during his service between the day before the effective date, and July 1, 1923, for such service, with interest thereon at the effective rate to July 1, 1923, upon the assumption that 1/12 of such 1 3/4% of such annual salary was due on the last day of each month of such service.
40 ILCS 5/8-183