1975

7.4

1986

6.8

2003

7.9

2014

7.5

2005

6.2

2016

7.5

2006

7.5

2016

5.7

2007

7.7

2012

6.6

2007

7.5

2004

8.1

2014

7.1

2009

7.1

2016

7.8

1988

8.1

1964

7.8

2001

8.3

2003

7.5

2004

7.6