The affiliated public employer shall contribute the following percentages of the salary of each member it employs and covers under municipal fire member coverage plan 4:
A. prior to July 1, 2022, twenty-one and nine-tenths percent of salary;
B. beginning July 1, 2022 and continuing through June 30, 2023, twenty-two and four-tenths percent of salary;
C. beginning July 1, 2023 and continuing through June 30, 2024, twenty-one and nine-tenths percent of salary;
D. beginning July 1, 2024 and continuing through June 30, 2025, twenty-three and four-tenths percent of salary; and
E. beginning July 1, 2025 and thereafter, twenty-three and nine-tenths percent of salary.