82% (2006)

76% (2006)

73% (2004)

74% (2002)

71% (2000)

61% (2007)

68% (2001)

63% (1998)

52% (2008)

69% (2005)

66% (2002)

58% (2004)

62% (2005)

51% (2007)

57% (1998)

72% (1998)

57% (1991)

52% (1999)

62% (2001)

49% (1997)