Each person operating for profit a gasoline filling station or pump in cities or towns, or within three miles thereof, shall, on October 1, of each year, pay the following annual privilege tax: In cities of 100,000 inhabitants and over, where only one pump or filler is used, $28 and, for each additional pump, $21; in cities or towns of 40,000 inhabitants and less than 100,000 inhabitants, where only one pump or filler is used, $21 and, for each additional pump, $14; in cities or towns of 12,000 inhabitants and less than 40,000, where only one pump or filler is used, $18 and, for each additional pump, $10; in cities or towns of 5,000 inhabitants and less than 12,000, where only one pump or filler is used, $14 and, for each additional pump, $7; in incorporated towns of 1,000 inhabitants and less than 5,000, where only one pump or filler is used, $7 and, for each additional pump, $5; in incorporated towns of less than 1,000 inhabitants, $3.50 and, for each additional pump, $2.50; and in all other places, whether incorporated or not, $2.50 and, for each additional pump, $2.50.