1999

7.4

2003

5.8

1996

6.6

2002

7.1

2005

6.4

2001

6.7

2006

5.4

2004

4.8

2001

6.1

1976

3.3

1993

5.7

1999

5.8

2004

5.8

2008

5.7

2005

5.2

2005

5.2

2008

5.8

2008

5.9

2008

5.7

2007

6.1