We're talking about a minimum, so it's not restrictive. The idea is to allow them to know that they'll have access to 5.4 per cent. If the budget changes, the $500,000 amount, as opposed to a percentage, becomes random, whereas the 5.4 per cent sets a base amount that they should be entitled to, which is more consistent with their needs.
On June 22nd, 2006. See this statement in context.