Year annual % 1961 -3.258929953073391 1962 7.1381755269392215 1963 2.9110563760741854 1964 -6.233211221526176 1965 -5.896514279325558 1966 8.846762444422083 1967 6.112649801558362 1968 1.9000484964096955 1969 -1.6861123797236388 1970 4.955509455932813 1971 2.401972321218196 1972 10.333400235043428 1973 -1.7452349296302003 1974 -18.186825768262835 1975 29.61960842479425 1976 -0.9131753264063747 1977 22.88737091126356 1978 3.746654951458254 1979 -2.212368053222889 1980 -4.339486854251135 1981 5.157566991257042 1982 3.0780547637852607 1983 -8.066767636375644 1984 -1.3115004277030664 1985 6.4165254089213875 1986 3.554143220761688 1987 6.629483491240734 1988 -1.0643316875450353 1989 -1.1946215915686906