Whenever there is presented to the body having in its charge the capital of the county school fund of any county or the city of St. Louis a petition, signed by qualified electors of the county or the city of St. Louis equal in number to five percent of the voters casting a ballot in the county or the city of St. Louis for the office of governor at the last preceding general election at which the office was voted upon, praying that the proposal be submitted to the qualified electors for making annual distribution of the capital of the liquidated school fund, the body shall cause an election to be held upon the proposal.