In a city initially classified as a second
-class city prior to January 1, 1993, that retained its second
-class city plan of government when the city reorganized as a noncharter code city, the terms of office of mayor, city clerk, city treasurer and councilmembers shall be four years, and until their successors are elected and qualified and assume office in accordance with RCW
29A.60.280, but not more than six councilmembers normally shall be elected in any one year to fill a full term.