Notwithstanding the provisions of any general or special law to the contrary, the minimum annual compensation of each regular police officer of the police department of any city or town which accepts the provisions of this section shall be not less than the following:
For the first year of service fifty-five hundred dollars.
For the second year of service six thousand dollars.
For the third and each succeeding year of service sixty-three hundred dollars.
Mass. Gen. Laws ch. 41, § 108G