1966

6.8

2013

6.7

1982

7.6

2004

6.8

2000

6.4

1988

6.7

2012

6.3

2001

5.1

1950

7.0

1994

6.5

1941

7.3

2003

6.9

1957

8.3

2008

4.5

1991

6.8

2007

7.6

2010

6.2

1971

6.3

1980

6.7