68% (2017)

73% (2009)

71% (2007)

62% (2014)

69% (2003)

73% (2008)

61% (2014)

66% (2005)

73% (1979)

50% (2013)

51% (2017)

57% (2015)

71% (2009)

58% (2010)

40% (1999)

0% (1988)