1993

6.8

2017

6.7

2015

7.7

2014

8.4

1999

7.4

2012

8.4

2010

6.7

2020

7.8

2018

8.0

1989

8.3

2018

7.8

2015

7.5

2003

7.6

2016

7.5

2017

8.4

2016

7.0

2014

8.3

2015

6.8

2007

8.5

2011

8.1