54% (1976)

71% (1970)

74% (1969)

42% (1976)

65% (1976)

63% (1973)

52% (1972)

63% (1973)

64% (1971)

41% (1967)

60% (1975)

61% (1973)

61% (1975)

47% (1973)

62% (1974)

53% (1974)

65% (1974)

48% (1973)

58% (1974)

46% (1974)