58% (1971)

70% (1982)

69% (1977)

60% (1985)

0% (1990)

50% (1978)

50% (1970)

67% (1970)

48% (1973)

52% (1971)

65% (1976)

59% (1987)

61% (1981)

63% (1981)

70% (1980)

58% (1981)

50% (1987)

52% (1969)

74% (1958)

46% (1960)