56% (1988)

56% (1989)

69% (1990)

47% (1988)

58% (1989)

45% (1989)

42% (1987)

61% (1990)

38% (1992)

57% (1989)

55% (1988)

40% (1989)

32% (1987)

54% (1988)

53% (1991)

60% (1993)

71% (1988)

44% (1987)

63% (1987)

59% (1987)