(1) The index number for a * quarter is the All Groups Consumer Price Index number, being the weighted average of the 8 capital cities, published by the * Australian Statistician in respect of that quarter.
(2) Subject to subsection (3), if, at any time before or after the commencement of this Act:
(a) the * Australian Statistician has published or publishes an * index number in respect of a * quarter; and
(b) that index number is in substitution for an index number previously published by the Australian Statistician in respect of that quarter;
disregard the publication of the later index for the purposes of this section.
(3) If, at any time before or after the commencement of this Act, the * Australian Statistician has changed or changes the reference base for the Consumer Price Index, then, in applying this section after the change took place or takes place, have regard only to * index numbers published in terms of the new reference base.