79% (1990)

57% (1991)

55% (1996)

72% (1989)

71% (1994)

64% (1994)

63% (1994)

58% (1996)

61% (1997)

76% (1995)

60% (1996)

40% (1996)

35% (1990)

49% (1992)

40% (1997)