The legislative power of each city shall be vested in, and exercised by the city council, composed of not fewer than 7 members, 4 of whom shall be elected by wards and 3 of whom shall be elected by electors of the city at large. For the first 20,000 inhabitants in the city, in addition to the original 5,000, there shall be 2 additional members of such legislative authority, elected by wards, and for every 15,000 inhabitants thereafter there shall be one additional member similarly elected. The total number of members of the council shall not exceed 17.
(R.C. § 731.01)