(a) 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 28,56028,600 28,660 48,400 48,500 58,07558,125 67,500 67,600 74,500 74,600287,700287,800319,625319,725777,113777,500
not less than nor more than
28,500 28,560
28,600 28,660
48,400 48,500
58,07558,125
67,500 67,600
74,500 74,600
287,700287,800
319,625319,725
777,113777,500
(b) 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.