151.7. Where a local municipality referred to in section 5 has availed itself, in respect of its roll of assessment that came into force on 1 January 2001, of the power provided for in section 253.27 of the Act respecting municipal taxation (chapter F-2.1), the city may, on or before the adoption of the budget for the fiscal year 2002, provide that the averaging of the variation in the taxable values resulting from the coming into force of the roll will continue for that fiscal year in respect of the sector concerned.