The General Assembly shall hold an election to fill vacancies occurring due to expiration of terms no earlier than the first day of April of the year the term expires and as necessary to fill unexpired terms which are caused by the death, resignation, or removal of a trustee, except that vacancies of unexpired terms of members elected by the Association of Citadel Men shall be filled in the same manner as is provided for by § 59-121-10. No elective member shall be elected or re-elected either by the General Assembly or by the Association of Citadel Men to fill any term of office the duration of which shall extend beyond the member’s seventy-fifth birthday. However, beginning with the elections for members of the board occurring on or after July 1, 1997, the seventy-fifth birthday limit no longer applies.