76% (1999)

72% (2000)

69% (1996)

70% (2010)

73% (2003)

77% (1997)

75% (1991)

72% (2013)

70% (2012)

69% (2017)

57% (1995)

64% (2007)

76% (2002)

71% (2008)

70% (2015)

70% (2001)

61% (2005)

61% (2004)

64% (2015)

58% (2017)