65% (2006)

55% (2002)

68% (2005)

64% (2001)

56% (2001)

60% (2005)

61% (2002)

63% (2005)

67% (1999)

61% (2003)

65% (1998)

63% (2005)

63% (1998)

64% (1995)

67% (1997)

65% (2002)

73% (1983)

58% (1996)

51% (1992)

51% (2005)