Year	2007 US$
1991	1479000000
1992	1514000000
1993	940000000
1994	679500000
1995	1091000000
1996	990100000
1997	903500000
1998	1302000000
1999	648500000
2000	847200000
2001	1479000000
2002	1538000000
2003	1426000000
2004	1337000000
2005	1339000000
2006	1587000000
2007	2610000000