§ 200. State board. There is hereby created in the department of taxation and finance a separate and independent state board of real property tax services, to consist of five members to be appointed by the governor, by and with the advice and consent of the senate. Of those five members appointed by the governor, one such person shall be an individual actively engaged in the commercial production for sale of agricultural crops, livestock and livestock products of an average gross sales value of ten thousand dollars or more. Said individual shall be appointed in the first instance to a term of eight years upon expiration of an existing term. Said initial term shall commence on the first day of January next succeeding the year in which the existing term shall expire. The governor shall designate one of the members as the chairman of the board, who shall serve as chairman at the pleasure of the governor. The members of the board shall be appointed for terms of eight years, commencing on the first day of January next following the year in which the term of his predecessor expired, except that the terms of the members first appointed shall expire as follows: one on December thirty-first, nineteen hundred sixty-one, one on December thirty-first, nineteen hundred sixty-three, one on December thirty-first, nineteen hundred sixty-five, one on December thirty-first, nineteen hundred sixty-seven, and one on December thirty-first, nineteen hundred eighty-two. Vacancies occurring otherwise than by expiration of term shall be filled for the unexpired term. All members shall receive necessary expenses incurred in the performance of their duties.