Year	constant 2015 US$
1990	382300000
1991	740650000
1992	1018420000
1993	719180000
1994	609130000
1995	717240000
1996	680120000
1997	446910000
1998	693100000
1999	853400000
2000	846250000
2001	797760000
2002	719890000
2003	476170000
2004	498500000