13. Valuation of property.
(1) The Commissioner shall provide for the determination of the value of all relevant properties (other than relevant properties specified in Schedule 4) in accordance with the provisions of this Act.
(2) Without prejudice to the generality of subsection (1) or section 19(5), where the Commissioner is satisfied that it is appropriate to do so, the net annual value of particular properties or classes of properties may be determined using general market data, or aggregated data (including data derived from statistical and computer-aided techniques), that are likely to be representative of a particular class of properties.