Year	constant 2015 US$
1960	48750000
1961	51790000
1962	44370000
1963	49880000
1964	58340000
1965	65300000
1966	100970000
1967	99150000
1968	97510000
1969	98870000
1970	119390000
1971	95430000
1972	64800000
1973	140210000
1974	181360000
1975	144200000
1976	130750000
1977	113200000
1978	117530000
1979	272700000
1980	498090000
1981	337240000
1982	286920000
1983	293540000
1984	294000000
1985	281800000
1986	317750000
1987	247890000
1988	353270000
1989	388130000
1990	488580000
1991	1216430000
1992	861040000
1993	428130000
1994	786440000
1995	735310000
1996	1054660000
1997	535750000
1998	805060000
1999	886080000
2000	766220000
2001	1391180000
2002	711250000
2003	1000260000
2004	1333850000
2005	819330000
2006	767470000
2007	791300000
2008	667780000
2009	718350000
2010	606610000
2011	588310000
2012	474960000
2013	431170000
2014	382110000
2015	457780000
2016	430980000
2017	549580000