Section 56 of the Principal Act is amended by substituting for subsection (1) the following:

"(1) In this section -

‘appropriate year’ means the financial year immediately following the effective date in relation to the valuation list that, for the time being, stands published in respect of the area of the rating authority concerned;

‘consumer price index number’ means the All Items Consumer Price Index Number compiled by the Central Statistics Office;

‘consumer price index number relevant to the appropriate year’ means the consumer price index number most recently published by the Central Statistics Office before the effective date mentioned in the definition of ‘appropriate year’ in this subsection;

‘consumer price index number relevant to the preceding year’ means the consumer price index number lastly published by the Central Statistics Office before the day that falls 12 months before the day on which the consumer price index number referred to in the preceding definition is published;

‘preceding year’ means the financial year that immediately precedes the financial year mentioned in the definition of ‘appropriate year’ in this subsection.".