1980

6.6

1981

6.5

2002

7.4

2008

5.5

1972

3.2

1966

6.1

2002

3.7

1986

5.2

1982

6.8

2006

6.0

2009

5.0

1994

5.3

2000

4.8

1984

6.1

1981

6.8

2003

7.1

1933

0.0

1940

2.0

1940

6.0

2013

6.9