57% (1970)

60% (1961)

57% (1974)

61% (1974)

61% (1968)

69% (1970)

63% (1970)

55% (1973)

69% (1991)

66% (1968)

55% (1980)

63% (1978)

51% (1992)

48% (1970)

65% (1962)

64% (1975)

52% (1970)

50% (1975)

56% (1970)

36% (1976)