1972

6.2

1974

6.3

1978

5.1

1987

6.8

1976

5.3

1993

7.2

1995

5.5

1974

5.2

2003

6.3

1972

3.8

1973

5.5

1980

5.3

1976

4.5

1974

5.4

1973

6.0

1980

5.7

1975

5.2

1982

5.5