1957

5.7

1997

6.5

1992

7.0

2008

5.2

2016

7.1

2017

7.3

2006

7.3

2007

6.0

1948

8.0

1976

6.6

1977

5.0

2002

6.8

2006

7.6

2008

6.3

1980

5.8

2018

6.6

2007

5.8

1991

0.0

1927

6.4

1991

6.2