Sec. 4. (a) For a county with a population of less than two hundred thousand (200,000), a local board of health is composed of seven (7) members, not more than four (4) of whom may be from the same political party.
(b) For a county with a population of at least two hundred thousand (200,000), a local board of health is composed of nine (9) members, not more than five (5) of whom may be from the same political party.