1982

5.9

1963

5.7

2009

7.3

1993

7.1

2004

6.5

2008

6.5

1987

7.1

2005

7.2

2005

6.0

1976

7.0

2006

5.2

2005

7.4

2009

4.2

1949

6.9

1989

5.5

1975

6.8

2006

6.1

1999

6.6