Upon the appointment of each alternate member, each alternate member shall serve an initial term, which shall expire at the end of the official year (to wit: March 31) next following such appointment, at which time such initial term shall expire. Thereafter, such alternate members, or any replacement for such alternate members, shall serve a term of two years, beginning on the first day of April following the expiration of the prior term and expiring on the last day of March two years thereafter. Upon the appointment of a second alternate member, said second alternate member shall serve an initial term to expire one year following the expiration of the then-current term of the first alternate member, and thereafter, such second alternate member, or any replacement for such second alternate member, shall serve a term of two years, beginning on the first day of April following the expiration of the prior term and expiring on the last day of March two years thereafter. It being the intention that, upon the appointment of two alternate members, the terms of the two alternate members shall expire on March 31, at the end of the official year, in alternating years.