The municipality shall have the following elected officers: one mayor, one municipal clerk and one municipal treasurer, all of whom shall be elected at large, and alderpersons , the number of which shall be as follows: In cities not exceeding 25,000 inhabitants, 8
alderpersons ; between 25,001 and 40,000, 10
alderpersons ; between 40,001 and 60,000, 14
alderpersons ; between 60,001 and 80,000, 16
alderpersons ; and exceeding 80,000, 20 alderpersons . Two alderpersons shall be elected to represent each ward.
65 ILCS 5/6-3-3