Year	constant 2015 US$
1960	180000
1961	5190000
1962	23410000
1963	32140000
1964	107800000
1965	93660000
1966	92070000
1967	102270000
1968	86100000
1969	118810000
1970	147700000
1971	138400000
1972	138890000
1973	180650000
1974	96020000
1975	194380000
1976	108690000
1977	80440000
1978	109160000
1979	81300000
1980	107640000
1981	94110000
1982	143650000
1983	156190000
1984	196210000
1985	155710000
1986	150350000
1987	133360000
1988	163140000
1989	208320000
1990	174580000
1991	190250000
1992	85140000
1993	130370000
1994	227760000
1995	166850000
1996	144520000
1997	50770000
1998	57740000
1999	63760000
2000	18590000
2001	12080000
2002	99990000
2003	-11600000
2004	42720000
2005	51910000
2006	30750000
2007	48030000
2008	53950000
2009	67800000
2010	92800000
2011	57270000
2012	61020000
2013	75960000
2014	96330000
2015	99170000
2016	41500000
2017	103740000