Year	constant 2015 US$
1960	-380000
1961	256160000
1963	230000
1965	11740000
1966	27450000
1967	167850000
1968	80000
1969	-950000
1970	-380000
1971	-60000
1972	640000
1973	970000
1974	1580000
1975	16950000
1976	56360000
1977	145770000
1978	118010000
1979	102090000
1980	107330000
1981	131870000
1982	140870000
1983	184970000
1984	242200000
1985	230150000
1986	263070000
1987	227030000
1988	250650000
1989	271540000
1990	370700000
1991	376950000
1992	430930000
1993	406440000
1994	601430000
1995	512840000
1996	565650000
1997	478180000
1998	454850000
1999	526620000
2000	431390000
2001	416470000
2002	567190000
2003	596610000
2004	1244720000
2005	441880000
2006	172820000
2007	251490000
2008	334970000
2009	231540000
2010	224170000
2011	179620000
2012	228220000
2013	259840000
2014	213470000
2015	401990000
2016	206530000
2017	218830000