1966

6.1

2003

6.3

2002

7.0

2004

6.9

1967

5.2

2006

6.5

1985

6.2

1993

6.5

1985

6.4

1999

6.2

2002

5.7

1996

6.9

2003

5.5

2009

6.1

2000

5.7

1996

6.6

2005

5.0

2001

6.8

2007

5.2

1997

6.1