51% (1978)

62% (1978)

50% (1975)

60% (1981)

68% (1984)

49% (1984)

64% (1980)

64% (1985)

70% (1970)

66% (1982)

71% (1974)

68% (1978)

50% (1976)

65% (1984)

59% (1970)

76% (1969)

78% (1977)

40% (1978)

57% (1975)

60% (1986)