1950

8.1

2014

7.4

2015

6.8

2009

6.4

2016

5.1

2014

6.9

2001

4.1

2014

5.7

2005

6.1

2014

7.2

2003

2.9

2009

5.0

2008

5.8

1992

5.7

2009

5.6

2014

5.9

1952

6.1

1941

6.0

2001

7.3

2010

5.7