Year	constant 2015 US$
1960	21245850000
1961	25895140000
1962	24966660000
1963	27229430000
1964	27565140000
1965	29944020000
1966	30300510000
1967	30743880000
1968	28779900000
1969	26078090000
1970	26780850000
1971	27123510000
1972	25455750000
1973	28496810000
1974	34900830000
1975	40899230000
1976	38420630000
1977	34825100000
1978	36624940000
1979	36637890000
1980	41647510000
1981	40971630000
1982	40082850000
1983	37848550000
1984	38414420000
1985	40861070000
1986	37697700000
1987	35234670000
1988	36034460000
1989	37915480000
1990	47847870000
1991	49714770000
1992	43400990000
1993	42068740000
1994	42435090000
1995	37462620000
1996	36266560000
1997	33804450000
1998	37376100000
1999	39525220000
2000	37652250000
2001	41694050000
2002	44386900000
2003	41350920000
2004	43735430000
2005	72443530000
2006	63502850000
2007	51630410000
2008	54867970000
2009	53725020000
2010	50315540000
2011	52615690000
2012	51472570000
2013	58716470000
2014	56562910000
2015	58247690000
2016	60186940000
2017	58492300000