Year	constant 2015 US$
1960	7280720000
1961	6753040000
1962	7380900000
1963	10254520000
1964	12015160000
1965	12318610000
1966	11022240000
1967	12201840000
1968	8834290000
1969	7839420000
1970	7571660000
1971	8376500000
1972	6453150000
1973	7179580000
1974	9440120000
1975	12898010000
1976	11992250000
1977	8569400000
1978	8823920000
1979	9108540000
1980	11505450000
1981	10127460000
1982	10480230000
1983	9990540000
1984	10171910000
1985	9999800000
1986	9930230000
1987	8543110000
1988	9285070000
1989	9666030000
1990	8324810000
1991	10589720000
1992	8407430000
1993	6750260000
1994	8345820000
1995	5493860000
1996	5994980000
1997	5700250000
1998	6109070000
1999	5258660000
2000	5202120000
2001	8034390000
2002	8991130000
2003	6958360000
2004	7629390000
2005	10070550000
2006	9722390000
2007	11279260000
2008	11393170000
2009	14176670000
2010	14741150000
2011	15292500000
2012	12827010000
2013	12755010000
2014	14249350000
2015	15683950000
2016	13944210000
2017	14617760000