1983

6.5

1988

5.2

2012

4.9

2008

7.0

2006

6.3

1994

4.6

2005

7.5

2020

7.2

1999

6.7

2009

6.8

2001

5.8

2015

6.6

2013

6.1

1986

5.8

2011

7.9

2010

4.6

2004

6.0

2008

7.1

1963

7.1