1981

5.2

1996

6.5

1997

4.5

1997

5.4

2000

5.0

1977

6.0

1974

6.0

1994

8.0

2001

0.0

2002

0.0

2012

5.5

2008

7.0

2009

0.0

1994

3.9

1971

6.4

1970

6.2

1998

7.5

2003

6.7

1996

6.8

1998

6.0

1996

0.0