Members of the zoning commission shall serve in such office for a period of two years and until their respective successors are appointed and qualified; provided, however, that of the members first appointed to such zoning commission after the final adoption of the ordinance codified in this chapter, four shall serve for a period of two years and three for a period of one year. Vacancies occurring upon such zoning commission shall be filled by the appointment of new members to serve the balance of the term of those persons ceasing to be members of such commission. (Ord. 188 § 3, 1954)