66% (2009)

67% (2008)

54% (1985)

73% (1975)

61% (2003)

71% (1981)

63% (2006)

59% (2008)

62% (2000)

67% (1977)

66% (1992)

64% (1997)

54% (1992)

60% (1982)

67% (1991)

66% (2009)

61% (2007)

52% (1994)

58% (2002)

53% (1989)