1980

6.3

2015

6.7

2005

7.4

2006

6.7

2002

7.7

1989

7.0

2007

7.4

2007

7.8

1940

7.1

1963

7.2

2007

6.7

2014

6.1

2010

6.6

1983

7.9

2004

7.3

2007

7.1

1980

6.7

1960

8.4

1988

5.7

1994

6.2