2002

8.6

2009

8.3

2008

6.7

2020

8.4

1999

7.4

2006

7.9

1994

6.7

1998

7.2

2009

7.4

2012

7.7

2004

8.3

2001

8.1

2011

7.4

2017

7.9

2020

9.3

1993

8.2

2014

6.9

1979

6.8

2005

8.4

2012

7.0