1976

7.3

1959

5.5

1970

7.6

2012

6.3

1962

6.4

1955

7.2

2017

8.0

2020

6.8

1939

7.5

1966

6.2

2018

7.0

2017

7.2

2009

5.8

2011

6.6

2014

6.9

2017

6.6

1980

5.4

1973

6.8

1965

6.8

2011

6.7