2008

6.1

2005

4.3

2007

3.0

2000

5.7

1971

4.4

2006

5.4

2001

6.1

1976

3.3

2006

7.1

1999

7.8

2003

7.2

2001

6.7

2006

6.3

2001

7.3

2005

6.7

1994

5.8

1993

5.0

2004

6.5

2008

5.7

1979

5.3