Year Percent 1961 -5.26092 1962 4.83788 1963 0.62924 1964 -8.13421 1965 -8.00696 1966 6.48213 1967 3.16291 1968 -0.59609 1969 -3.84239 1970 2.85321 1971 1.86689 1972 9.952 1973 -2.81785 1974 -21.00388 1975 21.59896 1976 -10.45819 1977 9.56785 1978 -7.57583 1979 -11.46552 1980 -10.02944 1981 1.73133 1982 2.34341 1983 -9.07548 1984 3.4366 1985 7.45521 1986 1.91733 1987 3.1391 1988 -2.59606 1989 -1.99669 1990 -2.8016