Year	constant 2015 US$
1960	80190000
1961	60600000
1962	23450000
1963	64760000
1964	65000000
1965	61810000
1966	78750000
1967	114060000
1968	123380000
1969	106630000
1970	109890000
1971	119270000
1972	124870000
1973	106240000
1974	139690000
1975	128750000
1976	139000000
1977	146500000
1978	109620000
1979	71800000
1980	66930000
1981	120760000
1982	197250000
1983	117180000
1984	118590000
1985	116510000
1986	113820000
1987	119000000
1988	99250000
1989	120060000
1990	74450000
1991	180310000
1992	111630000
1993	136200000
1994	90190000
1995	129810000
1996	92700000
1997	129890000
1998	97150000
1999	95590000
2000	93660000
2001	79190000
2002	73510000
2003	59990000
2004	27050000
2005	52820000
2006	59580000
2007	107350000
2008	125790000
2009	134060000
2010	116300000
2011	88970000
2012	101800000
2013	117950000
2014	56290000
2015	59380000
2016	88540000
2017	138340000