72% (1973)

57% (1974)

65% (1976)

49% (1974)

69% (1979)

54% (1968)

45% (1970)

50% (1970)

65% (1971)

52% (1982)

55% (1981)

59% (1979)

67% (1986)

52% (1971)

62% (1980)

58% (1969)

59% (1977)

38% (1981)

54% (1967)

39% (1969)