Year	constant 2015 US$
1960	2621850000
1961	4066770000
1962	4681740000
1963	4432860000
1964	6458880000
1965	7145830000
1966	7198700000
1967	6742160000
1968	7153110000
1969	6554090000
1970	6406470000
1971	6645980000
1972	6615080000
1973	7058060000
1974	9669490000
1975	11315990000
1976	10311590000
1977	11152300000
1978	13012960000
1979	14796860000
1980	15738510000
1981	16482550000
1982	17586120000
1983	17255420000
1984	18629250000
1985	20562460000
1986	20392190000
1987	20075920000
1988	21322950000
1989	22746770000
1990	23635910000
1991	22770500000
1992	23182010000
1993	22297350000
1994	23110980000
1995	20443190000
1996	17677230000
1997	17228440000
1998	17439420000
1999	16042870000
2000	16762500000
2001	18962630000
2002	24328810000
2003	27547370000
2004	26465190000
2005	32243730000
2006	39522490000
2007	31375570000
2008	33013050000
2009	37213510000
2010	37940980000
2011	38311780000
2012	38320920000
2013	39444020000
2014	36679450000
2015	39850480000
2016	38833870000
2017	42847340000