76% (2019)

56% (2018)

43% (2018)

65% (2017)

59% (2014)

77% (2012)

66% (2013)

54% (2010)

70% (2010)

69% (2000)

54% (1975)

50% (1976)

67% (1951)

63% (2003)

65% (2007)

68% (2004)

67% (1984)

46% (1994)

68% (1995)

66% (1997)