2006

1.0

2001

3.9

2002

3.2

1999

3.2

1970

3.8

1989

4.2

1974

4.1

1982

5.2

1991

4.5

1976

3.3

2005

3.8

2011

3.1

0.0

1975

3.2

1995

4.4

1993

5.5

2007

0.0

2013

4.9

2013

4.3

2012

6.1