2000

7.4

1999

7.3

2008

8.7

2009

5.6

2007

6.6

1967

4.3

2003

7.1

2006

6.5

1978

6.8

1998

7.2

2009

6.2

2009

5.6

2005

6.8

1993

7.8

2007

9.8

2002

6.7

2003

5.2

2010

5.6

2003

8.7

2006

6.0