1976

3.3

2005

3.8

1999

1.0

2008

4.0

1973

3.7

1967

5.3

1975

5.8

2001

3.9

2002

3.2

1999

3.2

1970

3.8

1989

4.2

2011

3.1

1981

1.0

1961

4.3

1954

0.0

1963

4.6

1976

5.6

1973

5.4

2004

4.7