I'm sure my former colleagues from the Department of Finance would be happy to answer this question more fully. But I'll make the important point that for government revenues, nominal GDP is very important. Nominal GDP is not CPI plus real growth; it's the GDP deflator plus real growth.
Paul will find the page, but in this document we have the evolution of the GDP deflator or the chain-link price, which is running higher because of firm commodity prices and stronger terms of trade than might have been predicted. So when you look at those sensitivities, look at the real growth and the deflator.