Year	constant 2015 US$
1960	17889220000
1961	18478760000
1962	19747220000
1963	21505290000
1964	20875260000
1965	21949760000
1966	20627280000
1967	22589190000
1968	19824750000
1969	18041660000
1970	19662140000
1971	20392820000
1972	18729670000
1973	24645220000
1974	30273250000
1975	38330510000
1976	37701290000
1977	33101590000
1978	33011530000
1979	36019120000
1980	38836390000
1981	35678460000
1982	34448710000
1983	33276580000
1984	33929540000
1985	34962190000
1986	33547600000
1987	30264490000
1988	28894950000
1989	29301480000
1990	38912970000
1991	40069720000
1992	33855520000
1993	29222790000
1994	30941680000
1995	24560660000
1996	27098330000
1997	22061310000
1998	24382990000
1999	23464410000
2000	22549140000
2001	27609700000
2002	26382970000
2003	24628500000
2004	23165270000
2005	25958530000
2006	24977240000
2007	24699210000
2008	29214620000
2009	32113120000
2010	33989590000
2011	34532220000
2012	32560660000
2013	43379220000
2014	41389200000
2015	45216930000
2016	50610180000
2017	52531760000