(1) This part shall only apply in counties having a population, according to the 1980 federal census or any subsequent federal census, of: not less than nor more than 28,500 28,560 28,600 28,660 48,400 48,500 58,075 58,125 67,500 67,600 74,500 74,600 287,700 287,800 319,625 319,725 777,113 777,500
(2) This part shall also apply in any county having a metropolitan government having a population of more than one hundred thousand (100,000), according to the 1990 federal census or any subsequent federal census.