Year constant 2015 US$ 1990 382300000 1991 491000000 1992 684180000 1993 468950000 1994 458820000 1995 472180000 1996 582800000 1997 370840000 1998 639050000 1999 798280000 2000 773330000 2001 728300000 2002 653980000 2003 410340000 2004 429350000