73% (1984)

58% (1985)

59% (1988)

65% (1986)

54% (1989)

67% (1987)

42% (1991)

53% (1995)

63% (1985)

47% (1988)

44% (1992)

34% (1994)

57% (1988)

63% (1981)

39% (1990)

55% (1985)

42% (1986)

30% (1991)

52% (1991)

40% (1985)