71% (1963)

73% (1964)

75% (1963)

75% (1970)

78% (1964)

73% (1975)

67% (1965)

56% (1972)

78% (1967)

63% (1965)

61% (1973)

54% (1971)

57% (1971)

64% (1973)

59% (1967)

68% (1974)

54% (1974)

52% (1975)

58% (1965)

61% (1970)