The commissioners serving on the date of ratification of this charter shall serve until the expiration of their terms or until their successors are elected and qualified. In the regular municipal election in 2017, and quadrennially thereafter, two (2) commissioners shall be elected to serve four (4) year terms in those positions whose terms are then expiring. In the regular municipal election in 2019, and quadrennially thereafter, three (3) commissioners shall be elected to serve four (4) year terms in those positions whose terms are then expiring.