2017

6.8

2006

6.4

2015

8.4

1985

6.7

2010

7.0

2004

7.0

1999

7.3

1994

7.4

2005

6.9

1980

6.7

2010

6.1

2006

7.0

2010

6.8

1989

7.2

2014

4.8

1925

8.0

2004

7.3

2017

5.6

2013

6.3

2014

5.6