1991

3.6

1941

6.2

2008

7.5

1999

7.2

2010

6.4

2009

7.1

1981

7.2

2013

4.8

2007

7.7

2021

1.0

2021

5.7

1961

6.9

2014

6.5

2010

7.1

2013

7.0