72% (1981)

65% (1984)

47% (1984)

79% (1976)

39% (1977)

67% (1977)

56% (1979)

66% (1976)

38% (1978)

48% (1977)

52% (1978)

59% (1978)

51% (1976)

50% (1979)

65% (1979)

49% (1995)

51% (1983)

47% (1976)

60% (1975)

77% (1974)