68% (2012)

68% (2005)

69% (2006)

65% (2011)

61% (2003)

69% (2009)

56% (1992)

68% (2010)

55% (2007)

70% (2006)

70% (2007)

64% (2001)

81% (1991)

10% (1999)

72% (1996)

0% (1987)

73% (1986)

0% (1988)