1992

6.0

2011

6.7

2002

7.6

2004

3.2

2005

5.9

2008

6.7

2008

5.5

2008

5.8

1980

5.3

1981

5.4

1955

7.3

1995

6.3

1995

7.2

1967

4.1

1991

6.5

1948

4.8

2006

6.4

2002

6.5

2005

4.9

2006

6.4