73% (1973)

57% (1974)

65% (1976)

54% (1968)

53% (1971)

50% (1974)

63% (1971)

54% (1967)

69% (1979)

43% (1970)

59% (1979)

49% (1975)

40% (1981)

58% (1977)

49% (1977)

0% (1972)

58% (1969)

52% (1970)

38% (1972)

59% (1981)