The Board of Estimates shall obtain from the Director of Finance the “assessable base” of the District, which shall constitute a listing by property and a calculation of the sum of assessments on properties subject to the Supplemental Tax. Properties subject to the tax shall include all properties within the District except:residential units in a condominium building, whether or not the units are owner-occupied; all other buildings used exclusively for residential purposes, other than a building that contains 4 or more residential rental units; properties containing 4 or fewer residential units, with a non-residential use on the ground or first level only, if the property owner can document, in the manner approved by the Board of Estimates, that the owner:operates the non-residential use; and occupies a residential portion of the property as their primary residence; and properties otherwise exempt under:this subtitle; <cite data-doc="City of Baltimore, Md., Charter" data-path="II|§(63)">City Charter Article II, § (63)</cite>; or any other applicable law. The Board of Estimates shall determine with finality the assessable base on which the Supplemental Tax will be based. Funding for Authority operations shall be provided by a supplemental property tax (the “Supplemental Tax”) on the assessable base of the District as determined under subsection (a) of this section. The Supplemental Tax shall be assessed and collected in conjunction with the property taxes assessed and collected by the City (the “Regular Tax”), unless otherwise established by the Board of Estimates. Except as otherwise provided in this subtitle:the Supplemental Tax shall be enforced in the same way as the Regular Tax is enforced; all provisions that apply to assessments, refunds, collections, and enforcement of the Regular Tax apply to the Supplemental Tax; and credits that apply to the Regular Tax do not apply to the Supplemental Tax unless otherwise specifically provided by Ordinance. The Supplemental Tax rate shall be determined as follows:Any increase in the rate of the Supplemental Tax must be approved by a majority of the Board’s voting members. For the first full budget year, the rate of the Supplemental Tax shall be set to raise revenues equal to the costs of the Financial Plan. For any year after the first full budget year, the rate of the Supplemental Tax may be adjusted to yield revenues equal to the costs of the Financial Plan. That rate, however, may not be increased by more than 10% a year unless the increase is approved by 80% or more of the property-owner representatives on the Board. Exempt from the Supplemental Tax are the poles, conduits, tunnels, pipe lines, manholes, and other similar surface or subsurface structures, including their equipment, owned and controlled by a public service corporation, located on, over, or under streets, alleys, or other public ways or lands, the construction of which is authorized by the City, and the installation of which is regulated and supervised by the Department of Transportation. Ord. 07-417 Ord. 09-132 Ord. 15-435 Ord. 17-039 Ord. 18-143