1967

7.7

1984

7.1

1985

6.7

2006

7.0

2003

7.0

2001

6.9

1952

6.3

2000

6.9

2005

6.7

1980

5.1

2016

6.5

2016

10.0

2000

7.6

2006

6.2

1977

7.5

2004

6.8

2006

7.6

1983

4.5

2017

7.2

1977

8.8