City council members in a city under the city manager plan of government shall be nominated and elected as provided in section 32-538. The number of city council members shall be determined by the class and population of the city. In cities having one thousand or more but not more than forty thousand inhabitants as determined by the most recent federal decennial census or the most recent revised certified count by the United States Bureau of the Census, there shall be five members, and in cities having more than forty thousand but less than two hundred thousand inhabitants as determined by the most recent federal decennial census or the most recent revised certified count by the United States Bureau of the Census, there shall be seven members, except that in cities having between ten thousand and forty thousand inhabitants as determined by the most recent federal decennial census or the most recent revised certified count by the United States Bureau of the Census, the city council may by ordinance provide for seven members. The terms of office of all such members shall commence on the first regular meeting of such city council in December following their election.