64% (1973)

56% (1976)

57% (1969)

61% (1974)

55% (1968)

52% (1969)

58% (1976)

52% (1969)

70% (1991)

73% (1967)

42% (1971)

50% (1975)

57% (1968)

63% (1968)

68% (1968)

64% (1977)

50% (1977)

70% (1968)

50% (1970)

47% (1974)