The rate of tax imposed by this chapter shall be 11.5 percent of the gross income from garbage collection and disposal activities conducted in the city. [Ord. 2005-03-026; Ord. 10907 § 1, 1997; Ord. 10559 § 2, 1994; Ord. 10266 § 1, 1991; Ord. 9881 § 2, 1988; Ord. 9751, 1987; Ord. 9521 § 1, 1985; Ord. 9388 § 2, 1984].