73% (1964)

73% (1975)

75% (1963)

66% (1965)

71% (1963)

77% (1967)

75% (1970)

77% (1964)

61% (1973)

68% (1974)

56% (1972)

63% (1965)

59% (1967)

64% (1973)

58% (1965)

63% (1967)

57% (1971)

61% (1963)

60% (1973)

45% (1972)