1982

7.6

2006

6.4

1992

6.2

1982

6.0

2009

7.5

2014

6.8

2007

7.7

2003

7.3

2020

6.5

2006

6.7

2010

7.1

2013

7.5

2006

6.7

1974

6.1

2008

6.5

2002

10.0

1999

5.9

2004

6.7