78% (1983)

68% (2006)

60% (1994)

50% (1980)

60% (1950)

59% (1983)

69% (1994)

73% (1963)

76% (1974)

78% (2007)

50% (1983)

66% (2006)

53% (1966)

50% (1982)

61% (1996)

80% (1992)

72% (1991)

85% (2004)

63% (1997)

62% (1987)