67% (1981)

48% (1984)

43% (1983)

66% (1981)

60% (1987)

61% (1983)

71% (1979)

63% (1980)

59% (1984)

70% (1984)

63% (1985)

62% (1980)

59% (1982)

61% (1985)

76% (1980)

53% (1985)

62% (1981)

55% (1983)

65% (1990)

63% (1984)