The people of the city, by their approval of the ordinance from which this chapter was derived at the election provided for in section 4-2-3 of this chapter, hereby authorize the board of commissioners, by ordinances duly enacted, to make such administrative and technical changes or additions in the method and manner of administration and enforcing this chapter as may be necessary or proper for efficiency and fairness, except that the rate of the tax herein provided shall not be changed without approval of the qualified electors of the city as provided by law. (1980 Code § 32-36)