76% (1978)

78% (1976)

78% (1973)

57% (1974)

55% (1967)

73% (1981)

58% (1967)

67% (1970)

69% (1983)

50% (1968)

55% (1975)

52% (1968)

67% (1977)

50% (1972)

59% (1969)

52% (1973)

49% (1970)

57% (1983)

51% (1969)

53% (1974)