An annuitant who has received an initial increase under this Section, shall be entitled, on each January 1 following the granting of the initial increase, to an increase of 3% of the original monthly retirement annuity for increases granted prior to January 1, 1990, and equal to 3% of the total annuity, including previous increases under this Section, for increases granted on or after January 1, 1990. The original monthly retirement annuity for computations under this subsection (b) shall be considered to be $83.34 for any annuitant entitled to benefits under Section 16-134. The minimum original disability retirement annuity for computations under this subsection (b) shall be considered to be $33.34 per month for any annuitant retired on account of disability.
On January 1, 1987, any annuitant whose retirement annuity began on or before January 1, 1977, shall receive an increase in the monthly retirement annuity equal to 8 per year of creditable service times the number of years that have elapsed since the annuity began.
40 ILCS 5/16-136.1