77% (1969)

75% (2005)

76% (2001)

69% (1967)

70% (1972)

70% (1976)

70% (1994)

74% (1999)

60% (1984)

73% (1962)

60% (1970)

68% (1966)

68% (1979)

63% (1975)

68% (1968)

68% (1977)

58% (1972)

61% (1979)

55% (1973)

67% (1969)