(1) All cities of the first class having a paid fire department shall pension all firefighters of the paid fire department who were serving as such on August 7, 1965, and who did not elect coverage under the provisions of sections 35-204 to 35-215 as they existed prior to January 1, 1984, whenever such firefighters shall have first served in such fire department for the period of twenty-one years and shall elect to retire from active service and go upon the retired list.
(2) Such pension shall be paid by the city in the same manner as firefighters upon the active list are paid. Such pension shall be at least fifty percent of the amount of salary such retiring firefighter is receiving at the time he or she goes upon such pension list.
(3) Any such firefighter who retires on or after age fifty-five with less than twenty-one years of service shall receive a pension of at least fifty percent of the salary he or she was receiving at the time of his or her retirement multiplied by the ratio of the years of service to twenty-one.
(4) At the death of any such retired firefighter, the same rate of pension, as is herein provided for, shall be paid to the surviving spouse of such deceased firefighter during such time as the surviving spouse shall remain unmarried and, in case there be no surviving spouse, then the minor children, if any, of such deceased firefighter, shall be paid such pension during their minority to the age of eighteen years, except that as soon as a child of such deceased firefighter shall become eighteen years of age, such pension as to such child shall cease.
(5) Firefighters subject to subsection (1) of this section shall be subject to sections 16-1029 to 16-1032 but shall be exempt from sections 16-1024, 16-1025, 16-1027, 16-1028, and 16-1033.