1992

8.4

2007

8.1

2017

7.3

2020

9.4

7.6

2007

5.7

2017

6.0

2000

7.7

2007

6.9

2008

6.5

1941

7.0

2000

6.4

1973

6.2

2010

7.3

2018

5.2

1997

4.0

2003

5.0

2007

6.0