1987

8.4

1995

6.4

2015

8.7

2000

7.6

1998

6.8

2010

7.7

2016

7.0

2022

7.0

2014

8.3

2013

7.5

2007

7.8

2008

8.1

2004

7.9

2006

7.1

1980

6.1

2006

7.4

2001

7.6

2019

8.4

2018

8.1

2019

7.3