67% (1971)

57% (2006)

60% (1995)

52% (1969)

77% (1957)

68% (1975)

63% (1975)

63% (1965)

68% (1969)

73% (1964)

67% (1980)

68% (1980)

54% (1972)

67% (1952)

76% (1978)

79% (1952)

64% (1997)

57% (1982)

63% (1987)

69% (2002)