1969

8.3

2017

9.2

2013

7.7

2006

6.5

2015

7.0

1992

5.5

2003

6.1

2011

7.2

2017

7.2

2016

7.4

2016

5.9

1989

7.3

2009

7.6

2009

7.6

1997

7.8

2010

4.6

2012

6.0

2017

6.8

1993

5.6

2017

4.5