74% (1997)

74% (1999)

66% (1997)

73% (1995)

66% (1993)

74% (1998)

50% (1992)

54% (1995)

64% (1992)

54% (1996)

57% (1997)

62% (1997)

57% (1998)

50% (1996)

55% (1999)

50% (1996)

37% (1991)

67% (1998)

52% (1997)

58% (1998)