66% (1975)

73% (1976)

75% (1972)

64% (1973)

72% (1975)

61% (1975)

64% (1975)

62% (1975)

62% (1973)

63% (1972)

69% (1973)

64% (1975)

58% (1972)

64% (1976)

54% (1971)

47% (1966)

37% (1968)

58% (1972)

50% (1972)

63% (1972)