Year	constant 2015 US$
1960	920000
1961	24510000
1962	34730000
1963	52610000
1964	116140000
1965	100190000
1966	91240000
1967	102190000
1968	128610000
1969	115160000
1970	105520000
1971	106810000
1972	109490000
1973	112590000
1974	153580000
1975	140950000
1976	148450000
1977	193490000
1978	263000000
1979	254330000
1980	190260000
1981	143140000
1982	179470000
1983	267840000
1984	276390000
1985	269700000
1986	324600000
1987	200290000
1988	316320000
1989	310970000
1990	354080000
1991	268430000
1992	283430000
1993	123960000
1994	156990000
1995	217070000
1996	172560000
1997	151470000
1998	163170000
1999	90250000
2000	96810000
2001	66840000
2002	71400000
2003	59400000
2004	70170000
2005	86160000
2006	80690000
2007	113390000
2008	283430000
2009	471920000
2010	361200000
2011	467380000
2012	217070000
2013	201410000
2014	186060000
2015	200250000
2016	164970000
2017	338130000