Section 108F. Notwithstanding the provisions of any general or special law to the contrary, the minimum annual compensation of each fire fighter, permanently employed, in the fire department of any city or town which accepts the provisions of this section, except a fire fighter who, by virtue of section sixty-one of chapter thirty-one is not regarded as a tenured employee, shall be not less than the following:
For the first year of service five thousand five hundred dollars.
For the second year of service six thousand dollars.
For the third and each succeeding year of service six thousand three hundred dollars.