1997

6.0

2007

7.0

1992

7.4

1994

6.2

2009

6.7

1978

7.5

1958

7.1

1967

7.7

1931

7.1

1937

7.9

1996

7.3

1980

4.3

2006

7.0

2005

6.8

2002

6.6

1979

7.5

2008

6.5

1933

5.8

1977

6.8

2007

0.0