67% (2018)

53% (2017)

55% (2015)

59% (2015)

51% (2014)

64% (2013)

50% (2012)

49% (2013)

62% (2011)

55% (2010)

56% (2010)

63% (1987)

59% (2010)

52% (2000)

53% (2002)

52% (1990)

76% (2004)

58% (2009)

66% (2006)

65% (1946)