1999

6.5

2006

7.1

1997

7.5

1940

7.9

1958

8.2

2001

6.2

1970

0.0

2008

5.8

2005

5.6

1987

6.8

2017

6.9

1997

7.1

2004

7.3

2006

5.5

1987

6.8

1981

6.5

1996

6.7

1997

5.4

2007

5.3

2018

5.8