76% (1970)

77% (1971)

70% (1972)

72% (1972)

63% (1973)

77% (1973)

73% (1961)

79% (1971)

67% (1972)

73% (1972)

71% (1968)

72% (1970)

67% (1971)

65% (1974)

53% (1975)

68% (1962)

61% (1973)

68% (1971)

67% (1963)

67% (1974)