Sec. 6. (a) In addition to the increase provided in IC 5-10.2-5-6, the monthly benefit payable after June 30, 1978, to a member, or a survivor or beneficiary of a member who retired or was disabled:
(1) before July 2, 1962, is increased by three percent (3%);
(2) after July 1, 1962, and before July 2, 1967, is increased by two percent (2%); and
(3) after July 1, 1967, and before July 2, 1972, is increased by one percent (1%).
(b) This section does not apply to benefits payable in a lump sum.