The term of office of each member of the board is four years and until a successor is appointed and qualified. The terms must be so arranged that no more than four terms expire on the thirty-first of July of each year. The governor shall fill all vacancies by appointment but in case of a vacancy before the expiration of a term, the appointment must be for the residue of the term only. The board, at least six months in advance of filling an expired term, shall communicate with the governor’s office regarding specialty areas to be filled on the board. The governor’s office shall take this information into consideration when filling vacancies. No member of the board may serve thereon for more than two full terms.