61% (2007)

60% (1994)

64% (1977)

52% (1927)

58% (2002)

70% (1988)

69% (1970)

65% (1953)

48% (1979)

74% (2002)

70% (1973)

45% (1992)

60% (2002)

63% (1997)

55% (1984)

70% (1992)

77% (1991)

61% (2003)

78% (1973)

50% (1971)