Year constant 2015 US$ 1990 2652650000 1991 6641660000 1992 3750540000 1993 2758320000 1994 4025590000 1995 5584350000 1996 3030740000 1997 2898710000 1998 4045390000 1999 4806700000 2000 5592650000 2001 5623090000 2002 3892500000 2003 4780350000 2004 5480270000 2011 230000