The terms of the members first appointed under this section shall be so determined that to the greatest practical extent, the expiration of the terms shall be distributed, in a case of regular members, evenly over the first four (4) years after their appointment; in the case of alternative members, evenly over the first two (2) years after their appointment; provided that the initial terms of no regular member shall exceed four (4) years and the initial term of no alternate member shall exceed two (2) years. Thereafter, the term of a regular member shall be four (4) years; and the term of an alternative member shall be two (2) years.