Year	constant 2015 US$
1990	2233880000
1991	5612160000
1992	3142470000
1993	2319400000
1994	3564820000
1995	5039240000
1996	2477220000
1997	3965960000
1998	4658330000
1999	5089600000
2000	5289050000
2001	4019420000
2002	3621990000
2003	3520400000
2004	4141970000