1995

8.5

1996

9.4

2010

5.7

2002

6.5

1988

6.2

2006

6.3

2003

6.3

1989

5.7

2016

6.7

1981

7.0

1988

6.5

2006

6.7

2010

5.7

2003

6.8

1993

6.6

2002

6.3

1971

5.9

2013

6.5

2001

9.9

2010

6.8