Year	constant 2015 US$
1991	21980000
1992	148920000
1993	70710000
1994	70470000
1995	80950000
1996	89590000
1997	161040000
1998	193340000
1999	217880000
2000	201330000
2001	205680000
2002	152860000
2003	151930000
2004	246250000