1991

8.1

2023

7.4

2001

6.3

2015

6.0

2014

6.5

2009

8.5

5.6

1992

6.7

1996

5.7

1977

6.5

6.8

2020

7.2

2010

5.5

2023

6.1

2006

6.6

1920

6.2

1933

5.0

2017

6.1

1986

5.8