Year constant 2015 US$ 1990 3279550000 1991 6622210000 1992 6438260000 1993 6264890000 1994 6229540000 1995 8289560000 1996 4689990000 1997 3771550000 1998 4726300000 1999 6497240000 2000 6891540000 2001 5865230000 2002 5191630000 2003 5144150000 2004 5888230000 2011 230000