76% (1978)

77% (1976)

79% (1973)

71% (1983)

74% (1981)

52% (1968)

57% (1974)

58% (1968)

59% (1969)

49% (1970)

55% (1970)

50% (1970)

58% (1967)

50% (1968)

50% (1972)

40% (1973)

55% (1968)

45% (1969)

62% (1975)

68% (1967)