Year	constant 2015 US$
1960	1550000
1961	12590000
1962	36920000
1963	33720000
1964	112970000
1965	123930000
1966	119040000
1967	127870000
1968	149690000
1969	153280000
1970	135530000
1971	164460000
1972	173960000
1973	255680000
1974	393650000
1975	299700000
1976	262910000
1977	340920000
1978	418810000
1979	458310000
1980	444370000
1981	494960000
1982	500290000
1983	433480000
1984	451520000
1985	452820000
1986	533850000
1987	448280000
1988	457360000
1989	431620000
1990	453630000
1991	578860000
1992	554230000
1993	626580000
1994	559070000
1995	563280000
1996	491960000
1997	484600000
1998	525800000
1999	527250000
2000	283640000
2001	574890000
2002	620940000
2003	647080000
2004	701910000
2005	741360000
2006	925590000
2007	881680000
2008	878860000
2009	993910000
2010	961190000
2011	849500000
2012	1045590000
2013	938970000
2014	1013350000
2015	997850000
2016	1027490000
2017	865020000