1924

6.8

1969

6.0

1987

6.0

2007

7.6

1975

7.7

1983

5.9

2017

5.0

2004

7.0

2020

5.9

1988

5.5

1960

5.0

1936

6.2

1974

7.5

1940

6.1

1935

7.0

2011

4.8

1947

6.3

2019

6.7

2020

8.1

1975

8.5