1975

6.2

1997

5.4

1973

5.5

1985

5.4

1998

5.0

1980

3.5

2017

0.0

1981

7.0

2003

0.0

1991

7.5

1983

6.7

1976

5.8

1991

5.8

1971

0.0

2013

5.6