2011

9.5

2009

8.5

2013

5.7

1995

5.9

1967

7.1

2000

6.3

2012

6.2

1982

6.1

2012

5.6

2017

5.9

1920

6.7

1984

6.3

1999

6.0

2016

4.6

1970

6.0

1988

6.9

1968

6.4

1976

7.6

1998

5.6

1966

6.1