78% (1967)

72% (1970)

71% (1970)

71% (1971)

57% (1967)

68% (1968)

48% (1967)

56% (1964)

63% (1966)

58% (1966)

61% (1976)

60% (1968)

53% (1966)

51% (1975)

63% (1965)

56% (1965)

62% (1969)

54% (1970)

53% (1967)

52% (1967)