61% (1974)

64% (1973)

58% (1967)

58% (1976)

59% (1976)

50% (1969)

57% (1969)

55% (1968)

54% (1968)

62% (1969)

54% (1967)

42% (1971)

50% (1967)

73% (1967)

64% (1977)

63% (1968)

65% (1972)

50% (1977)

59% (1967)

44% (1967)