1963

5.7

1956

6.6

1975

5.1

1981

6.4

1971

7.4

1976

6.6

1960

5.9

1979

5.1

1987

5.3

1968

6.7

1980

6.6

1966

7.1

1967

5.8

1964

7.9

1966

6.0

1968

6.7

1960

5.0

1957

5.8