2005

6.2

2006

5.9

1997

6.6

1994

5.8

1982

6.0

2001

5.8

1986

6.6

2002

5.4

2008

6.5

1995

6.3

2003

6.6

1985

6.2

1999

6.1

1969

7.0

2001

6.1

1985

7.5

1994

6.5

2001

5.7

2003

6.7

1994

6.4