Year	constant 2015 US$
1960	124190000
1961	119510000
1962	144660000
1963	169370000
1964	184700000
1965	244550000
1966	283170000
1967	186660000
1968	50240000
1969	34400000
1970	102510000
1971	181830000
1972	256600000
1973	275240000
1974	714310000
1975	872070000
1976	1612430000
1977	1382670000
1978	1060750000
1979	853480000
1980	1254970000
1981	1148560000
1982	1414580000
1983	1014770000
1984	1329930000
1985	1012220000
1986	666000000
1987	815980000
1988	475590000
1989	573690000
1990	639460000
1991	383670000
1992	319620000
1993	402710000
1994	207940000
1995	188220000
1996	287740000
1997	446370000
1998	499020000
1999	588000000
2000	426970000
2001	525770000
2002	295140000
2003	285120000
2004	288700000
2005	309590000
2006	296490000
2007	226000000
2008	384900000
2009	518480000
2010	624740000
2011	428410000
2012	660720000
2013	955300000
2014	1046090000
2015	1785800000
2016	2301110000
2017	3183710000