Year % 1971 85.75766 1972 76.43676 1973 82.58536 1974 93.43187 1975 98.7474 1976 91.64358 1977 95.32957 1979 82.87002 1982 65.52519 1984 70.56039 1985 65.44159 1986 64.3893 1987 64.10999 1988 62.98938 1999 66.79382