The people of the city, by their approval of the sales tax ordinances at elections provided for, hereby authorized the board of city commissioners, by ordinances duly enacted, to make such administrative and technical changes or additions and enforcing this chapter as may be necessary or proper for efficiency and fairness, except that neither the rates of the taxes herein provided nor the use to which the revenue is designated shall be changed without the approval of the qualified voters of the city, as provided by law. (2013 Code)