2008

8.9

2011

6.0

1999

8.2

2007

6.8

2005

8.3

2007

8.1

1992

8.5

2008

8.1

1996

6.8

2007

7.9

1999

7.4

2009

7.6

1999

7.9

2016

8.0

2006

7.8

2000

6.9

2001

7.6

2000

8.0

1976

6.7

1980

8.6