50% (1967)

58% (1981)

65% (1973)

70% (1978)

60% (1969)

53% (1968)

0% (1980)

63% (1969)

65% (1971)

90% (1987)

63% (1966)

70% (1978)

0% (1991)

79% (2000)

50% (1951)

50% (1978)

50% (1985)

50% (1998)

50% (1982)

65% (1980)