1996

6.2

1994

8.3

1961

7.2

1941

7.0

1992

7.7

1991

7.7

2013

6.4

2008

6.9

2004

5.7

2008

8.1

2013

6.2

1995

6.8

1973

7.3

2015

6.1

2014

7.9

2009

8.0

2009

7.3

2012

6.2

2014

5.9

2010

7.7