Every person, firm or corporation conducting, managing or maintaining a hotel, apartment house or an activity of renting living quarters of any nature consisting of four (4) or more rental units whether or not all of the units are located on the same lot or parcel of property, not otherwise provided for in this chapter and chapter 5.04 of this title, shall pay a license tax based on the gross business receipts of the previous calendar year as set forth in the schedule of fees in section 5.08.020 of this chapter. (Prior code § 2223)