1956

6.2

2006

7.3

2002

6.7

2002

6.7

2008

6.9

2004

6.6

2005

6.7

1981

7.2

2007

6.2

1966

6.1

1964

7.2

1936

6.1

1999

5.6

2017

3.6

2017

4.6

1972

7.7

1993

6.3

1949

7.9

2006

6.3

1991

6.2