Year	constant 2015 US$
1960	74760000
1961	73230000
1962	91790000
1963	82110000
1964	64100000
1965	106160000
1966	218120000
1967	316460000
1968	362140000
1969	323650000
1970	303110000
1971	314320000
1972	287020000
1973	247590000
1974	303330000
1975	513330000
1976	547700000
1977	561920000
1978	846910000
1979	750710000
1980	838490000
1981	831330000
1982	943790000
1983	1081330000
1984	1067360000
1985	1090280000
1986	1014990000
1987	764620000
1988	919770000
1989	910150000
1990	1011370000
1991	1166030000
1992	820260000
1993	847470000
1994	691610000
1995	552800000
1996	542150000
1997	393530000
1998	522580000
1999	306120000
2000	316640000
2001	418170000
2002	435590000
2003	779520000
2004	535720000
2005	1224390000
2006	818210000
2007	580050000
2008	654320000
2009	660210000
2010	521260000
2011	510880000
2012	411810000
2013	364860000
2014	448750000
2015	426390000
2016	357140000
2017	291610000