59% (2007)

74% (1993)

65% (2009)

63% (2006)

71% (1981)

68% (2008)

62% (1982)

61% (2000)

66% (1992)

67% (1977)

73% (1975)

67% (1991)

61% (2003)

55% (1985)

65% (1997)

55% (1992)

52% (1994)

62% (1979)

58% (2007)

59% (1995)