77% (1971)

76% (1970)

58% (1968)

72% (1972)

65% (1974)

61% (1973)

73% (1961)

70% (1972)

67% (1972)

69% (1975)

63% (1965)

77% (1973)

71% (1968)

67% (1971)

78% (1971)

58% (1965)

73% (1972)

65% (1973)

53% (1975)

72% (1970)