67% (2009)

64% (2010)

64% (2008)

62% (2002)

66% (1999)

65% (2000)

57% (1997)

64% (1999)

69% (2012)

70% (2000)

58% (2003)

57% (2008)

63% (1999)

65% (1997)

57% (2000)

55% (1986)

58% (2012)

51% (1990)

53% (1997)

61% (2002)