Year	constant 2015 US$
1960	-69460000
1961	-138770000
1962	503550000
1963	314080000
1964	-342130000
1965	-50670000
1966	181560000
1967	116420000
1968	327560000
1969	80340000
1970	57820000
1971	55950000
1972	105790000
1973	68150000
1974	30090000
1975	61950000
1976	-2890000
1977	-3220000
1978	-49240000
1979	12370000
1980	28490000
1981	32040000
1982	30550000
1983	24850000
1984	38100000
1985	30680000
1986	31040000
1987	29010000
1988	35510000
1989	98860000
1990	101030000
1991	36880000
1992	39680000
1993	50050000
1994	30800000
1995	47690000
1996	42980000
1997	6690000
1998	54700000
1999	59430000
2000	117400000
2001	67700000
2002	81270000
2003	98780000
2004	51250000
2005	52720000
2006	59420000
2007	68730000
2008	53660000
2009	54550000
2010	49430000
2011	44110000
2012	46680000
2013	34390000
2014	38390000
2015	36610000
2016	43430000
2017	84560000