52% (1981)

55% (1977)

50% (1981)

63% (1972)

54% (1971)

57% (1973)

45% (1979)

30% (1976)

63% (1976)

41% (1977)

42% (1977)

49% (1974)

30% (1980)

0% (1984)

0% (1975)