A tax is imposed upon all persons engaged in the business of operating motor passenger buses within the corporate limits of the city, in the amount of $125 a year for the first motor passenger bus, and $50 a year for each additional motor passenger bus. Said tax herein imposed shall be due and payable in advance on May 1 of each year, and shall be paid to and collected by the City Clerk.
('71 Code, § 4-3-2)