1972

4.7

1971

3.6

1968

5.9

1970

6.3

1973

3.0

1970

6.1

1968

5.8

1966

6.0

1964

7.2

1968

5.4

1975

4.0

1972

0.0

1963

5.5

1967

6.3

1971

5.3

1977

2.0

1976

7.2

1966

4.5

1970

7.7

1964

0.0