72% (1973)

57% (1974)

65% (1976)

68% (1979)

59% (1979)

49% (1974)

64% (1971)

45% (1970)

54% (1967)

67% (1986)

54% (1968)

62% (1980)

52% (1971)

52% (1975)

53% (1970)

49% (1977)

58% (1969)

38% (1981)

38% (1972)

0% (1972)