1983 7.9

1982 7.3

1982 5.8

1982 7.1

1982 7.6

1982 7.5

1982 7.2

1982 7.9

1981 6.3

1981 6.9

1981 7.2

1981 7.1

1980 6.8

1980 7.5

1980 5.4

1980 7.7

1980 7.1

1977 6.9

1977 7.5

1976 6.8