Year	constant 2015 US$
1980	12856000
1981	20181000
1982	14383000
1983	48323000
1984	34140000
1985	40696000
1986	64815000
1987	101706000
1988	196667000
1989	254839000
1990	263124000
1991	349555000
1992	417926000
1993	372736000
1994	462776000
1995	343208000
1996	291754000
1997	366630000
1998	374797000
1999	404178000
2000	442884000
2001	435907000
2002	477654000
2003	381623000
2004	1093386000
2005	386888000
2006	390195000
2007	412454000
2008	507101000
2009	429526000
2010	567964000
2011	591699000
2012	527290000
2013	419698000
2014	367261000
2015	308030000
2016	338950000