2000

7.6

1989

8.3

2002

7.5

1989

8.0

2001

7.6

2001

8.0

2008

6.7

2007

7.6

1999

7.4

2009

7.4

1979

7.4

2003

7.5

1996

7.0

2002

8.3

1966

7.2

2005

7.7

2006

8.2

2006

7.8

2005

7.0

2008

8.1