Year	constant 2015 US$
1960	1778630000
1961	1588960000
1962	1575940000
1963	1866160000
1964	1254700000
1965	1700590000
1966	1648470000
1967	1843560000
1968	1668430000
1969	2311910000
1970	1949870000
1971	2167340000
1972	2095320000
1973	1543960000
1974	1259950000
1975	1139950000
1976	1068610000
1977	1037340000
1978	720510000
1979	621310000
1980	546550000
1981	1024930000
1982	341710000
1983	333990000
1984	202120000
1985	273580000
1986	179510000
1987	184630000
1988	179000000
1989	366270000
1990	732820000
1991	2880100000
1992	1911030000
1993	1590460000
1994	2221970000
1995	2257880000
1996	2791630000
1997	2661480000
1998	3744390000
1999	4284770000
2000	3930530000
2001	4195080000
2002	3054700000
2003	2778170000
2004	3296530000
2005	1315460000
2006	1439170000
2007	1316240000
2008	1377080000
2009	1341350000
2010	1492130000
2011	1397120000
2012	1387880000
2013	1339340000
2014	2080560000
2015	2438620000
2016	4624230000
2017	1973970000