Upon adoption of a system of classification of taxable property by the town of North Providence, all ratable property in the town of North Providence shall be classified by the assessor as follows:
(1) Class one: all motor vehicles and trailers subject to the excise tax created by chapter 34 of this title.
(2) Class two: all ratable tangible personal property.
(3) Class three: all residential real estate which consists of not more than five (5) dwelling units.
(4) Class four: all commercial and industrial real estate and all residential real estate which consists of six (6) or more dwelling units.
(5) Class five: owner-occupied mixed-use combination commercial and residential properties with five (5) units or less, and that the total commercial portion of the structure cannot occupy more than fifty percent (50%) of the entire square foot size of the structure itself.