Year	constant 2015 US$
1960	6833420000
1961	7711400000
1962	6906320000
1963	5988010000
1964	5315340000
1965	4235000000
1966	3805910000
1967	3005900000
1968	2760250000
1969	2915560000
1970	5335450000
1971	4849370000
1972	4820720000
1973	9136540000
1974	13312580000
1975	17805900000
1976	16835540000
1977	18204840000
1978	16739360000
1979	16196060000
1980	17078760000
1981	16834670000
1982	13834690000
1983	10904290000
1984	10630600000
1985	11310350000
1986	8644060000
1987	8567820000
1988	6200920000
1989	6415320000
1990	16966100000
1991	15779340000
1992	9355910000
1993	7597340000
1994	9000410000
1995	6356280000
1996	6877790000
1997	6914510000
1998	7134650000
1999	6797570000
2000	6372770000
2001	6971590000
2002	6369440000
2003	10002930000
2004	12019580000
2005	31176720000
2006	18304720000
2007	17724660000
2008	22405370000
2009	13059200000
2010	11720290000
2011	13988810000
2012	12317740000
2013	23210260000
2014	29047490000
2015	24471420000
2016	26107010000
2017	27610880000