Sec. 8.04. AMOUNT OF CREDITS TO MEMBER'S DROP ACCOUNT. The amount credited monthly to the member's DROP account:

(1) shall be increased as a result of any increase in the formula used in computing service retirement benefits under Section 5.04 of this Act that occurs after the effective date of the member's election to participate in the DROP but before the effective date of the member's retirement;

(2) shall be increased by any annual cost-of-living adjustments under Section 9.04 of this Act that occur between the effective date of the member's election to participate in the DROP and the effective date of the member's retirement but only as to amounts credited to the member's DROP account after a cost-of-living adjustment; and

(3) is subject to the limitations prescribed by Section 9.03 of this Act.