1972

6.2

2010

5.8

2014

5.4

2013

5.8

2017

6.9

2007

7.3

2016

6.7

2001

6.3

1958

8.2

2015

7.6

2014

6.2

2016

7.3

2008

7.5

2014

6.1

2013

6.5

1984

7.2

1985

7.7

2002

8.4

2015

6.7

2012

7.0