Year US Dollars 1963 -0.39254 1966 0.1368 1967 0.12119 1969 0.38271 1970 0.50844 1971 0.75134 1972 1.34827 1973 1.83224 1974 2.84441 1975 3.94785 1976 5.97185 1977 3.69756 1978 0.57466 1979 0.65292 1980 1.9463 1981 2.88246 1982 2.75105 1983 3.17745 1984 3.81919 1985 5.0838 1986 6.14655 1987 7.12145 1988 4.44022 1989 11.68903 1990 6.7244 1991 6.30907 1992 6.19572 1993 7.75655 1994 6.43122 1995 7.26026