Year current US$ 1973 0.22602955961490395 1974 81.71417978555861 1975 36.45643510394322 1976 58.527662157739826 1977 46.78577074634841 1978 47.164384040406766 1979 40.89837748801955 1980 144.09355728117896 1981 88.00316558540196 1982 74.77683898873019 1983 66.43192309169132 1984 85.18168700084544 1985 105.59035234588887 1986 131.5381180950092 1987 179.0133793705731 1988 340.98884713796616 1989 327.8688422224654 1990 199.82281439017325 1991 185.24000367228652 1992 197.31050598592228 1993 259.8499398693198 1994 147.8536234410364 1995 91.65687650687262 1996 158.47970679411677 1997 165.61297459853148 1998 151.25480572508388 1999 106.19074687968411 2000 87.7675372195231 2001 220.2844368816792 2002 607.3837191222052 2003 1.9383602243388836 2004 -1.7174752729038365 2005 55.858745748439375 2006 111.5757140221336 2007 74.01893053437179 2008 994.571242808527 2009 68.73070253351943 2010 242.17875540021308 2011 331.22465330450814 2012 455.5073600083433 2013 629.0953846182616