(1) Service credits earned by part-paid firefighters prior to July 1, 1981, will be computed and granted on the basis of the ratio of salary earned by the part-paid firefighter to the salary paid to a newly confirmed full-paid firefighter during the same time period.

(2) Service credits earned on or after , shall be granted under the assumption that all part-paid firefighters work 15% time. Employer and part-paid employee contributions to the firefighters unified retirement system will be based on an assumed salary for part-paid firefighters which is 15% of a newly confirmed full-paid firefighter's salary for the same time period.

(3) A part-paid firefighter will accrue a service credit of one month for each calendar month during which contributions are made; however, if and when such part-paid service is qualified into another system, or if such part-paid firefighter also has full-paid firefighter service credits, each calendar month of part-paid service shall be credited as only .15 month of service.