72% (1981)

47% (1984)

65% (1984)

39% (1977)

49% (1995)

79% (1976)

65% (1979)

67% (1977)

52% (1978)

59% (1978)

66% (1976)

51% (1976)

60% (1975)

67% (1980)

42% (1977)

38% (1978)

54% (1987)

44% (1986)

40% (1978)

58% (1976)