2007

5.7

2002

7.7

2008

6.1

2009

6.2

2002

6.5

1975

6.0

2002

4.5

1998

5.4

2001

5.5

2007

4.7

2009

5.3

2005

7.3

1974

6.9

2006

6.4

1980

6.3

2008

4.7

2003

5.5

1992

5.7

2003

3.9

1992

6.8