Year	constant 2015 US$
1960	1770870000
1961	2780070000
1962	2780030000
1963	2689860000
1964	1895960000
1965	1841490000
1966	2130510000
1967	1610320000
1968	1292420000
1969	1368280000
1970	1007820000
1971	1261530000
1972	1500210000
1973	1015310000
1974	590850000
1975	501070000
1976	941950000
1977	701220000
1978	519710000
1979	1456770000
1980	2360810000
1981	1925800000
1982	1683730000
1983	1036350000
1984	779630000
1985	734080000
1986	873020000
1987	784620000
1988	602260000
1989	464880000
1990	2338570000
1991	3855990000
1992	4106180000
1993	5943090000
1994	4591230000
1995	4671880000
1996	4803860000
1997	4167980000
1998	4833930000
1999	7533680000
2000	7701320000
2001	7630620000
2002	9636170000
2003	6137990000
2004	6039420000
2005	5356110000
2006	6541650000
2007	5733880000
2008	6756740000
2009	7624910000
2010	6848120000
2011	9211510000
2012	9007640000
2013	7887450000
2014	9062340000
2015	8534070000
2016	9658340000
2017	9458990000