1937

6.7

1983

6.0

2001

6.8

2000

7.1

1988

6.3

2006

5.4

2007

5.3

1998

7.0

1981

6.6

1984

5.0

2006

7.2

2003

6.0

2003

5.1

1980

6.7

2004

6.0

1999

6.7

1941

7.1

2014

7.0

1971

6.8

1964

7.8