The gravamen of the Commissioner's argument was that reference by the Tribunal to "the formula" as a relevant consideration when determining what was an appropriate rental increase, demonstrated it took into account the Consumer Price Index (Privately-owned dwelling rents expenditure class) for Canberra published from time to time by the Australian Statistician. This is the "index number" as defined in s 68(5). The Commissioner submitted that this index number was not a matter that could be taken into account by the Tribunal when assessing whether a rental rate increase was excessive or not. The only relevance of the index number, it was submitted, was in determining who bore the onus of proof as provided in s 68(2).
9. In dealing with this submission, we should commence by saying that the use of the expression "the formula" may have the effect of distracting attention from the language used in the Act and the scheme of review established by Part 5. It is plain that the index number does have an important role to play in the operation of s 68(2). However it does not follow that the express reference to the "index number" in s 68(2) and the fact it is defined in s 68(5), implies that it is a factor the Tribunal cannot take into account when undertaking the task required by s 68(3).
10. In our opinion, whether the index number can be taken into account depends on the meaning of the expression "any other matter the Tribunal considers relevant" in s 68(3)(j). That expression is in general and wide language and, presumptively, the only limit on matters the Tribunal can take into account, is that they must be matters which are relevant having regard to the function the Tribunal is performing and the scope, purpose and objects of the Act.
11. We have little doubt that circumstances might arise where the index number could be a relevant consideration. For example, the Tribunal may be required to consider whether a rental increase was excessive for a property for which there were no comparable premises. The property may, for relevant purposes, be unique. Its uniqueness may flow, for example, from its location, size or configuration of rooms. In those circumstances, we do not see why the index number might not be relevant in determining whether a rental increase was excessive. The index number might be a relevant consideration in other situations. Ultimately its relevance would depend on the Tribunal's opinion that, in the circumstances of a particular case, it was relevant.
12. Counsel for the Commissioner submitted that the matters listed in s 68(3) have a common characteristic, namely that they each related to the property in question. Thus, it was submitted, s 68(3)(j) must be construed ejusdem generis, and concerns only matters which shared this characteristic. As the index number did not share this characteristic it was not a matter which could be considered under s 68(3)(j). We make two observations about this submission. First, what is sometimes described as the ejusdem generis rule, should be deployed with considerable caution: see the discussion in Pearce and Geddes, Statutory Interpretation in Australia, fifth edition at 4.24.
13. Secondly, we do not accept that the matters listed in s 68(3)(a) to (h) have a common characteristic as narrowly as was characterised by counsel for the Commissioner. Rental rates for comparable premises (the matter identified in s 68(3)(g)) do not concern the property in question, at least directly. While they do indirectly (in the sense that they create a point of comparison with the property in question), that indirect relationship is no different in principle (only different in degree) from the relationship between the property in question and the index number. In our view the construction advanced by the Commissioner of s 68(3)(j) is too narrow. The Tribunal is entitled, if it considers it relevant, to consider the index number when assessing whether the rental rate increase is excessive or not.
14. One further matter should be noted. Section 68(2) requires two calculations and a comparison to be made. Somewhat simplified, the following must be done. The existing rent must be notionally increased by the index number producing an increase as a money amount. That increase is then increased by 20% producing a second money amount. That second money amount is then compared to the rental rate increase (viz. the increase sought by the lessor) to determine which is the greater. It would be wrong of the Tribunal to treat either the increase resulting from the first calculation (using the index number) or the increase resulting from the second calculation (using the 20%) as some sort of indicative benchmark (sanctioned by the legislation) of what might be a rent increase which was not excessive. On another view, s 68(2) calls for a comparison of percentages and not money amounts, but it is unnecessary for us to determine this question in this appeal. The point we are making is that those calculations and that comparison are made only for the purpose identified in s 68(2), namely to determine who must show that the rental rate increase is or is not excessive. That is not to say, however, that the index number is necessarily irrelevant in considering whether the rental rate increase is excessive. As we have just discussed, it may be relevant.
15. In our opinion, the appeal should be dismissed with costs.