1994

8.4

1989

5.9

2011

7.8

1998

6.8

1993

7.1

2006

7.5

2009

7.6

1999

8.6

1991

7.6

2010

8.5

2001

8.5

2015

8.2

2016

8.0

2005

8.6

2005

8.3

2005

8.2

2008

8.9

1985

7.5

2011

8.4

1988

6.8