If a question concerning representation is found to exist, the Labor Commissioner shall direct an election upon the following bases. Where an employee organization certifies to the employer that it has a membership enrollment, as evidenced by dues authorization cards, of at least 30% of the total number of employees in an appropriate unit, and if no other intervenor employee organization or organizations certifies that it has a membership enrollment of at least 10% of the total number of employees in said unit, then, in such event, a secret ballot election shall be held in which the employees in such unit shall be offered a choice between exclusive representation by such organization or of no exclusive representation. In the event that an employee organization certifies to the employer that it has a membership enrollment of, or authorizations to represent at least 30% of the total number of employees in an appropriate unit and if any intervenor employee organization or organizations certifies that it has a membership enrollment of at least 10% of the total number of employees in such unit, then in such event, a secret ballot election shall be held wherein the ballot shall offer a choice among each of said employee organizations or of no exclusive representation. In all elections held hereunder the employee organization receiving the majority of votes cast by the eligible employees in a unit shall be declared to be the exclusive representative of all employees in such unit. Provided, however, that if the majority of votes in said election is cast for no exclusive representative, then there shall be no representative designated for such unit. Provided further, that where none of the choices on the ballot receives a majority, a run-off election shall be conducted, the ballot providing for a selection between the 2 choices receiving the largest and second largest number of valid votes cast in the election. No election shall be conducted in any unit in which an election has been conducted within the preceding 2 years. The services of the State Department of Labor and Industry or any other impartial agency selected by the parties to the election shall be utilized for the purpose of conducting elections hereunder including any disputes which may arise in respect thereto. The Labor Commissioner shall announce publicly the results of any election and shall certify said results. City Code, 1976/83, art. 1, §126 Ord. 68-251