1946

5.0

1980

8.4

2001

7.0

2007

6.4

2000

6.3

1978

3.4

1996

6.8

2002

6.0

2011

5.6

2005

7.5

2006

7.0

2010

7.3

1983

5.5

2009

6.8

2011

6.6

2012

6.9

2013

6.4

2011

7.2

2018

5.5

2011

6.3