Upon adoption of a system of classification of taxable property by the city of Warwick, all ratable property in the city of Warwick shall be classified by the assessor as follows:
(1) Class 1: residential real estate consisting of no more than five (5) dwelling units, land classified as open space, and dwellings on leased land including mobile homes.
(2) Class 2: commercial and industrial real estate, residential properties containing partial commercial or business uses and residential real estate of more than five (5) dwelling units.
(3) Class 3: all ratable tangible personal property.
(4) Class 4: motor vehicles and trailers subject to the excise tax created by chapter 34 of this title.