Year	constant 2015 US$
1960	20640000
1961	20410000
1962	45070000
1963	122670000
1964	150360000
1965	305090000
1966	398330000
1967	304260000
1968	414090000
1969	443870000
1970	342330000
1971	311220000
1972	279390000
1973	177120000
1974	135970000
1975	424400000
1976	208170000
1977	277700000
1978	306940000
1979	412060000
1980	412910000
1981	331190000
1982	334680000
1983	259150000
1984	521630000
1985	469920000
1986	697480000
1987	685800000
1988	881380000
1989	1094270000
1990	773200000
1991	1171600000
1992	779090000
1993	812130000
1994	658150000
1995	722200000
1996	753710000
1997	619800000
1998	883100000
1999	756290000
2000	778730000
2001	905720000
2002	926110000
2003	1163630000
2004	1491660000
2005	1209330000
2006	1256080000
2007	1079180000
2008	1168020000
2009	1479190000
2010	1591140000
2011	1627460000
2012	1631130000
2013	1190640000
2014	1005340000
2015	1758740000
2016	1316220000
2017	1237060000