Section 40 ILCS 5/5-149 - Mortality tables and interest rates(a) Any annuity fixed for or granted to a present employee or future entrant who entered service prior to January 1, 1954, or to his widow, shall be computed according to the American Experience Table of Mortality.(b) Annuities for future entrants entering service after December 31, 1953, and for the widows and persons having a right to annuities or benefits through such future entrants, shall be computed according to the Combined Annuity Mortality Table.(c) All sums to the credit of a policeman for annuity purposes at the time he withdraws from service before age 50 shall be improved to his credit thereafter by interest, while he is out of service and has not entered upon annuity, until he attains age 57. Any annuity fixed for or granted to present employees or future entrants who entered the service prior to January 1, 1954, and who have not re-entered the service prior to the time the annuity has been fixed or granted, and any annuity fixed for or granted their widows, shall be computed according to the American Experience Table of Mortality.(d) The amount of widow's annuity or widow's prior service annuity which shall be fixed for the wife of any policeman while he is alive shall be a reversionary annuity provided from the sum to his credit for widow's annuity or widow's prior service annuity.(e) Interest on the annuities herein provided for policemen and their beneficiaries shall be computed in accordance with Section 5--120.