9. Reduction in value of immovable property: In the case where the value of classified immovable heritage property is reduced in relation to the previous year, every additional reduction rate obtained under section 2 shall be decreased by one-quarter of the percentage that such reduction in valuation is to the valuation of the previous year.
The decrease provided for in the first paragraph shall not apply to classified immovable heritage property as long as the valuation of such property has not been reduced below the value according to which the total reduction rate for a fiscal year equalled a reduction of one-half of the value entered on the valuation roll.
R.R.Q., 1981, c. B-4, r. 3, s. 9.