80% (1999)

72% (1996)

76% (1993)

69% (1992)

82% (1993)

58% (1994)

59% (1995)

71% (1995)

72% (1995)

70% (1995)

54% (1996)

70% (1995)

65% (1997)

61% (1996)

63% (1996)

62% (1998)

73% (1994)

65% (1994)

60% (1997)

65% (1990)