79% (1988)

70% (1992)

69% (2007)

78% (2002)

64% (2010)

72% (2008)

68% (2014)

60% (2010)

68% (2004)

63% (2010)

67% (2015)

69% (2007)

70% (2007)

53% (1999)

72% (2004)