Year	current US$
1970	1000000
1971	1000000
1972	9000000
1973	13000000
1974	5000000
1975	15000000
1976	31000000
1977	55000000
1978	28000000
1979	11000000
1980	20000000
1981	1000000
1983	1000000
1984	2000000
1985	18000000
1986	22000000
1987	17000000
1988	15000000
1989	19000000
1990	354000000
1991	1606000000
1992	328000000
1993	96000000
1994	923000000
1995	45000000
1996	129000000
1997	43000000
1998	72669999.8565018
1999	135330000.4303456
2000	242700000.97155532
2001	144200003.4153461
2002	168879996.135831
2003	145130000.77009204
2004	148600003.00407407
2005	22889999.3896484
2006	30940000.5340576
2007	21139999.3896484
2008	7389999.8664856
2009	3700000.04768372
2010	-29999.999329447703