77% (2005)

66% (2012)

68% (2009)

70% (1991)

69% (2010)

66% (1981)

76% (2007)

68% (1980)

64% (1987)

80% (1986)

67% (2007)

64% (1992)

65% (2009)

71% (2000)

80% (2010)

74% (2008)

0% (1975)

68% (2006)

58% (1971)

64% (2003)