78% (1967)

72% (1970)

71% (1970)

71% (1971)

53% (1966)

57% (1967)

61% (1976)

63% (1965)

68% (1968)

51% (1975)

58% (1966)

63% (1969)

63% (1966)

45% (1970)

61% (1968)

60% (1966)

48% (1967)

65% (1966)

56% (1964)

63% (1967)