Sec. 7. (a) All members of the board shall be appointed for a term of four (4) years except that of the first appointees. The initial terms are as follows:
(1) One (1) shall serve for a period of two (2) years.
(2) Two (2) shall serve for a period of three (3) years.
(3) Four (4) shall serve for a term of four (4) years.
(b) At the expiration of the respective terms, appointments shall be made to fill the vacancies for the following four (4) years.