(1) In addition to any increase under ORS 238.360, first effective for the month of December 1990, payable January 1, 1991, the monthly retirement allowance payable to or on account of any person who has retired as a member of the Public Employees Retirement System shall be increased by the following percentages:
(a) If the member was serving as other than a police officer or firefighter at the time of retirement, the percentage increase shall be:
(A) For a member with a combined total of 10 or more years of creditable service in the system and prior service credit but less than a combined total of 20 years, one percent.
(B) For a member with a combined total of 20 or more years of creditable service in the system and prior service credit but less than a combined total of 25 years, two percent.
(C) For a member with a combined total of 25 or more years of creditable service in the system and prior service credit but less than a combined total of 30 years, three percent.
(D) For a member with a combined total of 30 or more years of creditable service in the system and prior service credit, four percent.
(b) If the member was serving as a police officer or firefighter at the time of retirement, the percentage increase shall be:
(A) For a member with a combined total of 10 or more years of creditable service in the system and prior service credit but less than a combined total of 20 years, one percent.
(B) For a member with a combined total of 20 or more years of creditable service in the system and prior service credit but less than a combined total of 25 years, two and one-half percent.
(C) For a member with a combined total of 25 or more years of creditable service in the system and prior service credit, four percent.
(c) The monthly retirement allowance payable to or on account of a member with less than a combined total of 10 years of creditable service in the system and prior service credit at the time of retirement shall not be increased under the provisions of this subsection.
(2) In addition to any increase under ORS 238.360, first effective for the month of December 1990, payable January 1, 1991, the monthly retirement allowance payable to or on account of any person who has retired as a member of the Public Employees Retirement System shall be increased by a percentage equal to the percentage calculated under ORS 238.364 (4), less any increase provided to the retired member under subsection (1) of this section.
(3) The increased allowance provided in subsections (1) and (2) of this section shall be funded by employer contributions.