12. A lack of correspondence between the price and the value referred to in section 11 shall entail price adjustment, in accordance with that section, where that difference is caused by a difference between the market conditions existing on the date mentioned in that section and the market conditions existing on the date on which the sales is concluded, by a difference between the object of the sale and the unit of assessment or by any other characteristic or condition of the sale that has influenced the price.
In the case of a sale concluded before the second fiscal period preceding the fiscal period for which the median proportion is being determined, the market conditions existing at the date on which that sale is concluded are assumed, subject to any evidence to the contrary, to be different from the market conditions existing on 1 July of that second fiscal period.