You can check my numbers against those in the published ICANN budgets, but I think the table below is more or less accurate:

Fiscal Year     Approved Budget

1999...........$5,900,000
2000...........$5,024,000
2001...........$6,030,000
2002...........$6,015,000
2003...........$8,255,000
2004..........$15,830,000
2005..........$22,988,000
2006..........$30,977,000 (proposed)

ICANN is accepting comments on its latest budget at budget-comments@icann.org.