Primary elections for nominating candidates for Mayor and Commissioner shall be held in each ward on the Tuesday following the second Monday in September of each odd-numbered year. The two (2) candidates who receive the highest number of votes for each respective office shall have their names placed upon the general municipal election ballot for that office. If no more than three (3) candidates file nominating petitions for an office, a primary election shall not be held for that office and those candidates shall be declared the nominees for that office in the general municipal election.