(a) Any city of the first class in this state having a population of twenty thousand (20,000) or more but less than seventy-five thousand (75,000) inhabitants, according to the most recent federal census, may establish or continue a civil service system for the nonuniformed employees of these cities, either by action of the city council or other governing body of the city or by a local initiated measure.
(b) Any civil service system established or continued pursuant to this chapter shall cover such nonuniformed employees of the city as the ordinance establishing or continuing the system shall prescribe.