Year	constant 2015 US$
1991	630000
1992	15010000
1993	88340000
1994	144860000
1995	99520000
1996	158790000
1997	129380000
1998	109870000
1999	146770000
2000	134450000
2001	181430000
2002	145500000
2003	145790000
2004	106300000
2005	126840000
2006	126620000
2007	129740000
2008	102610000
2009	131700000
2010	64760000
2011	132980000
2012	146710000
2013	145350000
2014	118530000
2015	83440000
2016	50630000
2017	95840000