1976

7.6

1979

3.6

1975

5.1

1972

6.2

1968

7.2

1966

7.0

1969

7.0

1964

6.1

1976

5.2

1974

6.2

1965

7.0

1966

6.0

1963

6.6

1973

6.7

1964

7.0