Year	constant 2015 US$
1990	11570000
1991	189040000
1992	96300000
1993	81260000
1994	121060000
1995	133960000
1996	134370000
1997	105020000
1998	235060000
1999	501590000
2000	200160000
2001	294310000
2002	252870000
2003	219210000
2004	282770000