Year	constant 2015 US$
1991	21980000
1992	148920000
1993	70710000
1994	70470000
1995	80950000
1996	91600000
1997	165670000
1998	222810000
1999	233470000
2000	208760000
2001	216900000
2002	159430000
2003	157190000
2004	252530000