Year	constant 2015 US$
1990	22480000
1991	517860000
1992	221710000
1993	177040000
1994	233610000
1995	147340000
1996	240340000
1997	326160000
1998	355860000
1999	392780000
2000	476150000
2001	566410000
2002	505400000
2003	562560000
2004	753740000