1999

7.6

1967

7.6

2002

8.0

1984

7.1

1981

8.1

2003

8.0

2003

7.5

2004

7.0

2006

7.4

2006

5.4

1997

8.2

2003

7.2

1997

8.3

2000

7.9

2010

8.2

2010

8.0

1971

7.6

2005

7.8

1996

8.5

2007

1.0