60% (1981)

60% (1989)

69% (2006)

74% (1953)

66% (1946)

52% (1996)

62% (2008)

70% (2008)

54% (2001)

55% (2006)

57% (1998)

72% (2003)

62% (1975)

68% (1932)

67% (2010)

69% (1986)

69% (2005)

63% (1998)

60% (2008)

68% (1973)