1960

7.5

2003

6.7

2006

7.4

2005

7.0

2015

6.5

2005

6.2

2007

6.4

1977

6.2

1999

7.5

2017

7.2

2016

6.3

2016

6.7

2014

5.9

2004

6.1

1999

5.5

10.0

2008

6.8

2003

7.0

2003

6.7

1982

6.6