Nominations for Mayor and Aldermen shall be by petition and there shall be no party designation on any such petition of any candidate or on any ballot in any municipal election. Each nominating petition shall be signed by the candidate. In electing a Mayor at large, the petition shall be signed by fifteen voters for each thousand or major fraction thereof of the population as shown by the last census. No petition need be signed by more than fifty voters. If the candidate is to be voted on by ward, the petition shall be signed by at least five per cent of the voters of the ward. This percentage shall be based on the whole number of voters voting in the ward at the last annual election. Qualified voters as used in this section shall mean voters who are qualified to vote in the election for which said petitions were filed. The nominating petition of each candidate shall be filed at the office of the Finance Officer during normal business hours or as provided by State law or by ordinance.