Year	constant 2015 US$
1960	-10840000
1961	416460000
1962	196880000
1963	139100000
1964	-31020000
1965	251070000
1966	250740000
1967	280210000
1968	441340000
1969	349940000
1970	483330000
1971	239680000
1972	296690000
1973	267100000
1974	210470000
1975	195880000
1976	205300000
1977	149100000
1978	35410000
1979	166510000
1980	114870000
1981	218790000
1982	314600000
1983	297240000
1984	192520000
1985	323880000
1986	445840000
1987	255390000
1988	263120000
1989	148950000
1990	215790000
1991	360310000
1992	385400000
1993	559150000
1994	494050000
1995	339600000
1996	288310000
1997	116500000
1998	40670000
1999	59140000
2000	-21410000
2001	142800000
2002	190830000
2003	148220000
2004	159010000
2005	234780000
2006	281330000
2007	123970000
2008	151570000
2009	201700000
2010	458780000
2011	909390000
2012	406780000
2013	522390000
2014	731630000
2015	308590000
2016	809300000
2017	719090000