1995

8.6

1999

7.9

2014

8.3

2023

8.6

2011

7.4

2004

7.3

2013

7.5

2006

8.2

2015

8.0

2021

7.8

2016

8.6

2017

8.4

2016

8.5

2012

6.4

1990

8.3

2017

8.1

2005

8.2

2013

8.7

2005

7.5

1982

7.9