83% (2005)

82% (2001)

82% (1998)

79% (2000)

78% (2003)

79% (1999)

81% (1997)

73% (1998)

79% (1996)

82% (2000)

79% (2004)

76% (2002)

80% (1993)

81% (1999)

79% (2002)

82% (2002)

72% (2008)

65% (1998)

78% (1999)

71% (2002)