1995

5.6

1989

5.5

1987

5.2

1959

6.1

1996

6.5

2017

6.6

2012

6.5

2009

5.9

2003

6.8

1936

7.2

1986

6.2

1996

5.8

2006

6.1

2013

6.7

2017

6.9

1973

9.2

2007

6.7

2011

6.9

2003

7.3

2010

7.3