53% (1976)

75% (1969)

72% (1970)

63% (1973)

61% (1975)

47% (1973)

65% (1974)

42% (1976)

63% (1973)

65% (1971)

65% (1971)

65% (1976)

48% (1973)

58% (1974)

60% (1975)

61% (1974)

62% (1974)

61% (1973)

52% (1972)

50% (1974)