Year	constant 2015 US$
1960	2965070000
1961	3545390000
1962	3004860000
1963	2023950000
1964	1563690000
1965	994140000
1966	824150000
1967	695240000
1968	747960000
1969	802700000
1970	743110000
1971	709880000
1972	549320000
1973	526040000
1974	496830000
1975	777460000
1976	457400000
1977	378350000
1978	476610000
1979	236770000
1980	416730000
1981	405460000
1982	348160000
1983	228530000
1984	338100000
1985	479460000
1986	335490000
1987	356970000
1988	270290000
1989	256760000
1990	443640000
1991	273890000
1992	455860000
1993	431410000
1994	386130000
1995	337420000
1996	353950000
1997	319550000
1998	546440000
1999	184990000
2000	292350000
2001	302760000
2002	266030000
2003	281310000
2004	332720000
2005	356710000
2006	237230000
2007	351140000
2008	269370000
2009	261130000
2010	180020000
2011	164920000
2012	133330000
2013	179870000
2014	137980000
2015	87290000
2016	157930000
2017	185280000