73% (1973)

57% (1974)

65% (1976)

64% (1971)

50% (1974)

54% (1968)

68% (1979)

59% (1977)

45% (1970)

53% (1970)

62% (1980)

49% (1977)

52% (1975)

67% (1986)

32% (1972)

58% (1969)

50% (1970)

38% (1981)

52% (1971)

54% (1967)