Year	constant 2015 US$
1960	81030000
1961	105660000
1962	57530000
1963	55420000
1964	108160000
1965	122040000
1966	80510000
1967	71700000
1968	64060000
1969	75330000
1970	39010000
1971	9870000
1972	45540000
1973	51110000
1974	62690000
1975	50120000
1976	45900000
1977	96950000
1978	121060000
1979	116880000
1980	105670000
1981	77670000
1982	60150000
1983	74870000
1984	70470000
1985	54290000
1986	65410000
1987	77300000
1988	64030000
1989	51560000
1990	79080000
1991	75010000
1992	75110000
1993	75040000
1994	72890000
1995	68440000
1996	38240000
1997	34280000
1998	44860000
1999	36350000
2000	16710000
2001	41900000
2002	29860000
2003	39800000
2004	22930000
2005	49210000
2006	35910000
2007	48680000
2008	64280000
2009	53570000
2010	87470000
2011	114870000
2012	87240000
2013	109280000
2014	81320000
2015	92980000
2016	147490000
2017	143400000