1976

3.7

2007

6.3

1967

6.6

1995

5.8

2015

10.0

1995

7.2

2000

6.1

1993

8.0

1997

6.6

2001

6.2

2005

6.9

1933

7.6

2013

6.7

1962

6.9

2015

8.2

2006

5.3

1947

4.7

2006

5.9

2003

7.6

1997

6.0