Each disability benefit payable under Section 16-149, 16-149.1 or 16-149.2 shall be increased by 7% of the original fixed amount of such benefit on January 1, 1991 or January 1 following the fourth anniversary of the granting of the benefit, whichever occurs later. On each January 1 following the 7% increase, the disability benefit shall be increased by 3% of the current amount of the benefit, including prior increases under this Article. However, in the case of a disability retirement annuity granted under Section 16-149.2, the annual increases provided by this Section shall cease as soon as the recipient of the annuity qualifies for the automatic annual increases provided under Section 16-133.1.