82% (2006)

75% (2006)

73% (2004)

74% (2002)

61% (2007)

71% (2000)

68% (2001)

63% (1998)

65% (1997)

52% (2008)

68% (2005)

58% (2004)

52% (2007)

67% (2002)

72% (1998)

57% (1998)

61% (2005)

52% (1999)

57% (1991)

60% (2001)