1983 6.9

1983 6.5

1982 7.7

1982 7.3

1982 7.5

1982 7.3

1982 7.6

1981 7.8

1981 7.2

1981 6.6

1980 7.7

1980 8.1

1980 6.8

1979 7.6

1978 6.2

1977 6.9

1977 7.5

1976 7.7

1973 7.6

1973 7.5