2000

5.8

1991

3.5

1990

7.3

1981

7.0

2006

4.9

1988

5.4

2002

6.8

2008

6.3

2009

3.8

1975

4.0

2009

8.0

2001

5.3

2008

5.8

2010

5.3

2008

5.6

1994

6.0

2012

5.5

2011

3.7

2010

9.0

1967

6.1