Year current US$ 1970 3365178.6539285383 1971 3780391.126049856 1972 6121304.757878305 1973 8800519.91544169 1974 10462605.79828309 1975 -2699632.7287872476 1976 2300000.5750001436 1977 3450000.8625002154 1978 -3450000.8625002154 1979 7127583.749109052 1980 30558501.55488846 1981 17434327.849686466 1982 21559822.2903328 1983 -5116237.321604882 1984 610054.9252784393 1985 5743322.826343006 1986 18030382.069047607 1987 -9577447.909734271 1988 8797132.838465288 1989 8159601.811431603 1990 6299952.731029509 1991 8148291.665384064 1992 8730672.430079235 1993 8874629.6372235 1994 9547149.682972673 1995 10311310.597904377 1996 11226676.410777537 1997 11697145.071942868 1998 0 1999 0 2000 0 2001 0 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2012 0