1981

5.3

1996

6.6

2010

4.7

1997

5.4

2003

6.7

1977

6.1

1984

6.9

2006

0.0

2003

0.0

2002

2.0

2008

4.7

2007

6.0

1994

7.0

2001

7.1

1994

4.8

1970

6.1

2001

0.0

1999

5.5

2001

3.8

2001

5.9

2004

4.4

2004

5.0

2005

4.2

1995

7.8