Year	constant 2015 US$
1960	3108590000
1961	4122140000
1962	4651250000
1963	4584440000
1964	5792360000
1965	6212050000
1966	6300030000
1967	6016060000
1968	5684800000
1969	5267360000
1970	5147220000
1971	6013620000
1972	7317130000
1973	8952420000
1974	12686960000
1975	14820160000
1976	12416110000
1977	13990050000
1978	15988680000
1979	17559990000
1980	18726610000
1981	18694800000
1982	20293700000
1983	19175800000
1984	20511390000
1985	22652150000
1986	21946780000
1987	21944860000
1988	21515100000
1989	22128150000
1990	23127520000
1991	22168650000
1992	21755140000
1993	20465390000
1994	21332970000
1995	19535860000
1996	16342350000
1997	16626610000
1998	16480160000
1999	16182920000
2000	17241580000
2001	19918370000
2002	24234290000
2003	28902480000
2004	27819950000
2005	27741750000
2006	30016380000
2007	33267050000
2008	35915260000
2009	38575070000
2010	41780800000
2011	40553250000
2012	39351580000
2013	43571160000
2014	39708840000
2015	43212530000
2016	43445190000
2017	47947540000