1993

4.6

2012

6.0

2013

7.6

2011

6.1

1996

7.4

2009

7.0

1920

7.9

2009

7.2

2014

5.6

2007

4.9

2008

6.3

2010

8.2

2006

6.6

2015

6.0

2004

6.1

1994

6.6

2015

6.9

1986

6.2

1978

6.0

2008

6.1