We don't have that handy, but we'll get you the number very shortly.
Let me add that in what we have presented in our tables today on nominal GDP we've both shown the percentage changes, shown what was put in quite wisely by the government—a prudence factor, which we've identified—and shown it in absolute dollar terms in our budgetary table. So you can see the absolute figure and will see that it's roughly $30 billion lower for 2009 and roughly the same amount for 2010. The effective tax rate on that is about 15%, in terms of its impact on revenues overall.
In terms of the elasticity, Chris will comment.