75% (2008)

70% (2003)

74% (1995)

68% (1993)

72% (1999)

63% (1995)

68% (2007)

71% (1993)

56% (1999)

69% (1989)

66% (1998)

72% (1985)

65% (1999)

73% (1982)

64% (2005)

68% (1990)

59% (2001)

67% (1981)

63% (2011)

64% (2001)