62% (1972)

72% (1976)

65% (1975)

71% (1971)

72% (1972)

71% (1970)

53% (1971)

70% (1974)

70% (1967)

69% (1976)

66% (1975)

74% (1971)

69% (1974)

69% (1971)

57% (1973)

57% (1974)

66% (1973)

67% (1977)

62% (1973)

66% (1973)