1989

5.8

2008

8.7

2005

5.7

1986

5.8

2019

6.3

2010

6.1

1973

6.3

1991

4.9

2017

5.9

2003

6.2

2012

6.2

1970

6.0

1941

7.4

2013

7.5

2011

5.1

1990

4.4

2015

5.7

2020

6.5

2014

6.0