83% (2005)

83% (2001)

82% (1998)

79% (2000)

78% (2003)

82% (1997)

79% (1996)

80% (1993)

79% (2002)

79% (1999)

81% (2000)

74% (1998)

65% (1998)

67% (2001)

79% (2004)

76% (2002)

82% (1999)

76% (1996)

77% (1999)

72% (2008)