Year	constant 2015 US$
1971	160000
1973	2700000
1974	8450000
1975	5600000
1977	6520000
1978	13260000
1979	9840000
1980	10280000
1981	12640000
1982	10370000
1983	10390000
1984	10610000
1986	1920000
1987	3340000
1988	3110000
1990	6340000
1992	1290000
1993	99960000
1994	209510000
1995	184230000
1996	198310000
1997	161780000
1998	224200000
1999	204560000
2000	256830000
2001	420100000
2002	313050000
2003	387620000
2004	302480000
2005	390150000
2006	128020000
2007	148150000
2008	130860000
2009	132350000
2010	150300000
2011	112870000
2012	121680000
2013	72290000
2014	74420000
2015	94050000
2016	66820000
2017	77940000