All counties in the state having duly adopted a consolidated or metropolitan form of government pursuant to title 7, chapter 1, and all counties of the state having a population of six hundred thousand (600,000) or more, according to the 1970 federal census or any subsequent federal census, shall institute an inmate incentive program for workhouse prisoners, as set out in § 41-2-145.
T.C.A. § 41-2-144