Sec. 7. Postretirement Increase. (a) The monthly benefit payable on and after July 1, 1979, to a member, or a survivor or beneficiary of a member, who retired or was disabled:
(1) before July 2, 1962, shall be increased by six percent (6%);
(2) after July 1, 1962, and before July 2, 1967, shall be increased by four percent (4%); and
(3) after July 1, 1967, and before July 2, 1972, shall be increased by two percent (2%).
The increase specified in this section shall be based upon the date of the member's initial retirement or disability. This section does not apply to benefits payable in a lump sum.
(b) As a cost of living increase, the retirement, disability, and survivor benefits payable after June 30, 1979, to a member, or a beneficiary or a survivor of a member, who retired before August 1, 1978, shall be increased three percent (3%). The increase provided by this subsection is in addition to any other increase provided by law. This subsection does not apply to benefits payable in a lump sum.