(1) Any Option I firefighter, as provided in section 72-1434, Idaho Code, who has had the contributions remitted as provided in sections 72-1431 and 72-1432, Idaho Code, for the same number of years as he claims for service as a paid firefighter in Idaho, may at his option retire, and upon retirement shall be paid from the public employee retirement account [fund] a monthly sum during the remainder of his life equal to: after twenty (20) years of service and contributions, forty percent (40%) of the average paid firefighter’s salary or wage; or
(2) after twenty-one (21) years of service and contributions, forty-five percent (45%) of the average paid firefighter’s salary or wage; or
(3) after twenty-two (22) years of service and contributions, fifty percent (50%) of the average paid firefighter’s salary or wage; or
(4) after twenty-three (23) years of service and contributions, fifty-five percent (55%) of the average paid firefighter’s salary or wage; or
(5) after twenty-four (24) years of service and contributions, sixty percent (60%) of the average paid firefighter’s salary or wage; or
(6) after twenty-five (25) years of service and contributions, sixty-five percent (65%) of the average paid firefighter’s salary or wage.
(7) Any Option II firefighter, as provided in section 72-1434, Idaho Code, who has had the contributions remitted as provided in sections 72-1431 and 72-1432, Idaho Code, for the same number of years as he claims for service as a paid firefighter in Idaho, may at his option retire, and upon retirement shall be paid from the public employee retirement account [fund] a monthly sum during the remainder of his life equal to: after twenty (20) years of service and contributions, forty percent (40%) of his average salary or wage; or
(8) after twenty-one (21) years of service and contributions, forty-five percent (45%) of his average salary or wage; or
(9) after twenty-two (22) years of service and contributions, fifty percent (50%) of his average salary or wage; or
(10) after twenty-three (23) years of service and contributions, fifty-five percent (55%) of his average salary or wage; or
(11) after twenty-four (24) years of service and contributions, sixty percent (60%) of his average salary or wage; or
(12) after twenty-five (25) years of service and contributions, sixty-five percent (65%) of his average salary or wage.
All benefit payments to Option I firefighters shall be based on the average paid firefighter’s salary or wage in this state as defined in section 72-1431, Idaho Code. Option I monthly benefit payments shall vary annually according to the determination of the cost of living adjustment as set forth in section 72-1471, Idaho Code.