1957

8.0

1991

7.6

2015

6.9

2010

6.2

2018

6.3

1990

6.5

1994

8.5

2013

6.8

1994

5.7

1985

7.1

2015

5.4

2017

7.1

2012

6.1

2015

6.8

2015

6.6

2016

6.8

2020

6.4

2009

7.3

1953

7.2

2013

7.2