1974

6.7

1988

5.0

2005

6.6

2017

6.3

2023

6.8

2007

6.1

1992

7.0

2014

7.4

2009

5.9

2007

6.3

1988

6.7

1971

7.6

1955

7.3

2003

7.4

1940

7.9

2005

6.8

2005

6.0

1994

5.3

1999

8.0

2007

6.9