78% (1967)

71% (1970)

51% (1975)

63% (1969)

52% (1967)

45% (1976)

72% (1971)

64% (1967)

54% (1970)

71% (1970)

58% (1967)

60% (1966)

63% (1966)

53% (1966)

57% (1964)

62% (1968)

59% (1976)

45% (1970)

50% (1967)

68% (1968)