I think in some sense it is dictated by your point about the fiscal year. The fiscal year starts April 1. The budget, as I mentioned, is presenting the government's fiscal plan for the upcoming five years, so in this year we're preparing for budget 2013. I don't know what the date of that will be, obviously, but it's looking at the forecast from April 2013 through to March 2014 and the four following years.
March just tends to be the point at which you have as much information as possible, both in terms of what the economy is looking like from a historical perspective and also in terms of the fiscal numbers that we get on both the revenue and the spending sides through the year. In terms of forecasting, getting your starting point makes a huge difference in terms of the certainty that you can attach to your forecast. It's just that from a departmental perspective, the more information we have, the more confidence we have in our forecast.