78% (1971)

69% (1962)

77% (1970)

72% (1970)

70% (1972)

73% (1961)

66% (1972)

78% (1973)

67% (1971)

61% (1973)

72% (1961)

65% (1974)

72% (1972)

71% (1968)

63% (1965)

53% (1975)

67% (1974)

73% (1972)

62% (1969)

79% (1971)