12. The average value of the dwellings situated in the territory of a local municipality for the year of reference is the quotient obtained by dividing the second of the following amounts by the first:(1) the divisor is the total dwellings included in the units of assessment taken into consideration under section 13, according to the property assessment roll of the municipality that applies for that fiscal year; and
(2) the dividend is the result of the standardization of the total values determined in accordance with section 14, on the basis of the roll referred to in subparagraph 1 of the first paragraph.
The roll must be taken into consideration as it exists on the date on which it is reproduced in the summary of the municipality for the year of reference.
The standardization provided for in subparagraph 2 of the first paragraph consists in multiplying the total provided for in that paragraph by the factor established in respect of the property assessment roll of the municipality, under section 264 of the Act, for the year of reference.