2011

8.0

1980

8.4

1957

8.1

1990

7.4

1998

8.1

1984

8.0

1970

7.1

1988

5.5

2001

6.8

1948

7.5

1987

5.7

2007

7.6

2011

5.5

1960

8.3

1943

8.2

1933

6.9

2001

6.1

1989

6.2

2008

6.8