(a) Salary.— Each township commissioner may receive a salary, established by ordinance, as follows:

1. (1) In townships with a population of less than 5,000, a maximum of $3,145 per year.
2. (2) In townships with a population of 5,000 or more but less than 10,000, a maximum of $4,190 per year.
3. (3) In townships with a population of 10,000 or more but less than 15,000, a maximum of $5,450 per year.
4. (4) In townships with a population of 15,000 or more but less than 25,000, a maximum of $6,915 per year.
5. (5) In townships with a population of 25,000 or more but less than 35,000, a maximum of $7,335 per year.
6. (6) In townships with a population of 35,000 or more but less than 45,000, a maximum of $8,385 per year.
7. (7) In townships with a population of 45,000 or more, a maximum of $210 per year per 1,000 residents or fraction of 1,000.