Year	constant 2015 US$
1960	22410000
1961	37000000
1962	58240000
1963	65200000
1964	88310000
1965	94920000
1966	85630000
1967	89620000
1968	66950000
1969	90950000
1970	79360000
1971	83280000
1972	88110000
1973	100210000
1974	91450000
1975	107940000
1976	82930000
1977	78170000
1978	125960000
1979	130220000
1980	139330000
1981	123410000
1982	180720000
1983	534420000
1984	459670000
1985	591440000
1986	375560000
1987	411730000
1988	317770000
1989	378030000
1990	333370000
1991	237710000
1992	169110000
1993	136180000
1994	92650000
1995	37520000
1996	-16780000
1997	-6420000
1998	24450000
1999	-8240000
2000	27170000
2001	13220000
2002	9800000
2003	31210000
2004	15910000
2005	25330000
2006	21030000
2007	52270000
2008	58200000
2009	91130000
2010	80340000
2011	27590000
2012	27460000
2013	27780000
2014	48920000
2015	117170000
2016	100720000
2017	98950000