1996

6.5

2004

6.9

1980

4.8

1977

5.2

2005

7.1

2001

6.8

1982

0.0

1988

5.9

1989

6.2

1975

0.0

1984

7.3

1985

7.0

1983

6.2

1989

0.0

1980

5.5

1981

6.7

1973

6.4

1980

0.0

1991

4.5