2006

4.7

2002

3.7

1991

6.1

1990

6.1

2001

6.8

2004

1.4

2003

5.7

2004

6.1

2001

6.5

1979

6.7

2000

6.1

1999

6.8

2005

6.7

1995

6.5

2002

6.5

2006

6.4

2005

6.5

1998

4.4

1998

6.4

2004

6.6