Year	constant 2015 US$
1960	4290000
1961	45830000
1962	38950000
1963	83590000
1964	83150000
1965	89260000
1966	124100000
1967	89520000
1968	78670000
1969	69160000
1970	76960000
1971	65880000
1972	86670000
1973	98900000
1974	115310000
1975	130630000
1976	99650000
1977	138880000
1978	144980000
1979	141650000
1980	224520000
1981	380270000
1982	480260000
1983	618070000
1984	540480000
1985	706360000
1986	647930000
1987	771850000
1988	724990000
1989	744000000
1990	549560000
1991	445430000
1992	586190000
1993	573890000
1994	417070000
1995	355870000
1996	353420000
1997	353520000
1998	234990000
1999	231370000
2000	229580000
2001	330980000
2002	317960000
2003	232280000
2004	251760000
2005	213240000
2006	161820000
2007	102190000
2008	208410000
2009	251720000
2010	275220000
2011	271620000
2012	222040000
2013	154310000
2014	89610000
2015	89960000
2016	128970000
2017	147350000