Year	constant 2015 US$
1960	180000
1961	10560000
1962	27810000
1963	35230000
1964	133420000
1965	125360000
1966	103820000
1967	111470000
1968	89770000
1969	85100000
1970	93560000
1971	168370000
1972	102270000
1973	118100000
1974	131940000
1975	184170000
1976	173390000
1977	151700000
1978	164180000
1979	200070000
1980	188900000
1981	186890000
1982	189500000
1983	207050000
1984	192430000
1985	238990000
1986	264970000
1987	220930000
1988	247180000
1989	429190000
1990	373150000
1991	362260000
1992	363570000
1993	375890000
1994	322890000
1995	318420000
1996	330620000
1997	287000000
1998	262090000
1999	278070000
2000	357540000
2001	410890000
2002	310920000
2003	358990000
2004	424520000
2005	371310000
2006	412650000
2007	447280000
2008	564180000
2009	618140000
2010	645500000
2011	616730000
2012	461420000
2013	588400000
2014	532820000
2015	431330000
2016	493120000
2017	662590000