1976

3.3

2005

3.8

1973

3.7

1975

5.8

1967

5.3

2014

6.3

1973

5.5

2008

4.0

1998

2.4

1975

2.7

2013

4.3

2012

6.1

2012

5.8

1982

1.0

1977

2.5

2009

5.8

1991

4.7

1980

3.4

1981

3.1

1983

7.0