77% (1957)

65% (1977)

61% (1979)

70% (1968)

73% (1990)

73% (1987)

66% (1991)

71% (1958)

65% (1984)

50% (1988)

78% (1982)

70% (1984)

69% (1962)

66% (1966)

0% (1975)

0% (1974)

54% (1979)

55% (1986)

61% (1970)

63% (1981)