Illinois Statutes Chapter 40. Pensions § 5/5-127. Minimum amount of annuity of present employee

(1) If he is at least age 50 on withdrawal, his annuity, from and after such withdrawal, shall be 50% of the compensation attached to or appropriated for the rank in the police department which he may have held by civil service appointment on the day one year prior to the date of withdrawal from service. Beginning July 1, 1931, the compensation to be used shall be not less than that in effect on July 1, 1931;

(2) If he is less than age 50 on withdrawal, his annuity, beginning on the date he becomes age 50, shall be 50% of his salary at withdrawal but not in excess of $900 a year.