74% (1981)

76% (1985)

76% (1984)

70% (1983)

43% (1985)

62% (1983)

42% (1986)

65% (1982)

63% (1980)

61% (1986)

65% (1984)

64% (1981)

50% (1984)

50% (1986)

57% (1984)

62% (1984)

43% (1984)

50% (1985)

50% (1984)

43% (1983)