69% (1987)

73% (1988)

65% (1988)

64% (1977)

65% (1990)

60% (1978)

62% (1975)

43% (1971)

67% (1988)

52% (1987)

50% (1970)

59% (1985)

40% (1982)

62% (1985)

42% (1974)

60% (1984)

56% (1986)

39% (1973)

53% (1985)

57% (1988)