1998

8.7

2011

8.0

2016

7.4

2017

8.6

1987

8.0

2012

7.6

2015

8.2

1999

8.1

2012

6.8

1999

8.3

2001

7.5

1994

8.4

1995

7.3

2011

7.4

2012

7.3

2009

8.3

2015

8.4

1993

7.3

2015

8.3

2020

8.3