78% (1967)

71% (1970)

72% (1970)

64% (1965)

51% (1975)

72% (1971)

60% (1966)

63% (1969)

50% (1967)

62% (1968)

58% (1967)

62% (1965)

32% (1967)

63% (1966)

68% (1968)

53% (1966)

40% (1971)

64% (1967)

40% (1968)

61% (1968)