Year	constant 2015 US$
1960	3406230000
1961	4183160000
1962	5114660000
1963	4969290000
1964	6439400000
1965	7003640000
1966	7305690000
1967	6676080000
1968	6753520000
1969	6420150000
1970	6296600000
1971	7019380000
1972	8341550000
1973	11515910000
1974	16530530000
1975	18857930000
1976	15988200000
1977	18058960000
1978	19543490000
1979	23878140000
1980	24612470000
1981	24128950000
1982	24332020000
1983	22619600000
1984	23735410000
1985	25651320000
1986	25125710000
1987	24963580000
1988	24102660000
1989	24761990000
1990	27226550000
1991	26480900000
1992	24999920000
1993	23640240000
1994	26120650000
1995	23463310000
1996	20297230000
1997	19542750000
1998	20534190000
1999	19888180000
2000	20188320000
2001	23966450000
2002	28033720000
2003	32013880000
2004	31215460000
2005	31107050000
2006	33605210000
2007	36210460000
2008	39368420000
2009	45027610000
2010	46780680000
2011	46250910000
2012	47334320000
2013	51405790000
2014	47519830000
2015	52808180000
2016	56250610000
2017	63271270000