1972

7.2

2011

8.1

1952

7.9

1988

5.8

1982

6.9

1962

7.9

1983

6.5

2002

6.5

2000

6.8

1973

7.5

1970

6.5

1998

5.5

1929

7.8

2010

6.6

1953

6.6

2010

5.1

2006

7.8

1990

7.4

2004

7.1

1995

6.8