Year US Dollars 1961 0.09248 1962 0.62392 1963 12.8334 1964 13.17059 1965 17.49129 1966 9.5905 1967 5.74459 1968 4.75354 1969 6.69295 1970 5.44044 1971 3.98948 1972 2.91205 1973 2.18204 1974 3.15296 1975 4.15553 1976 3.56843 1977 1.9414 1978 2.91819 1979 2.99377 1980 3.39584 1981 -2.67788 1982 4.12223 1983 5.07141 1984 4.3638 1985 6.05108 1986 16.11352 1987 28.42196 1988 5.03763 1989 4.08371 1990 13.45421 1991 -1.46526 1992 4.56631 1993 1.10512 1994 15.48341 1995 18.05292 1996 11.49658 1997 25.39883 1998 11.00885 1999 20.29293 2000 -1.17099 2001 -4.61688 2002 -7.00613 2003 -2.31983 2004 -1.11668 2005 -1.76031 2006 8.92572 2007 14.78127 2008 6.67 2009 4.78165 2010 3.07737