Year US Dollars 1960 3.07286 1961 3.83022 1962 2.88829 1963 2.48398 1964 3.50867 1965 0.11508 1966 7.12294 1967 8.20255 1968 5.29071 1969 3.43519 1970 17.74668 1971 16.28386 1972 11.92758 1973 1.72122 1974 1.1993 1975 7.45316 1976 1.69332 1977 49.31663 1978 2.09878 1979 7.73844 1980 4.02348 1981 0.29995 1982 4.01591 1983 3.48263 1984 2.53758 1985 2.93577 1986 23.27233 1987 72.7707 1988 -7.10942 1989 -3.30945 1990 1.86301 1991 -3.81401 1992 -4.5978 1993 -4.57431 1994 -3.4478 1995 2.22269