Year	constant 2015 US$
1990	23170000
1991	380750000
1992	197720000
1993	156080000
1994	227790000
1995	196590000
1996	173620000
1997	173170000
1998	683080000
1999	502770000
2000	788910000
2001	568580000
2002	268150000
2003	361890000
2004	342010000