66% (1986)

70% (1981)

59% (1986)

67% (1980)

64% (1989)

64% (1986)

62% (1990)

62% (1988)

62% (1990)

58% (1989)

64% (1982)

62% (1984)

56% (1986)

61% (1984)

65% (1983)

56% (1989)

68% (1990)

65% (1990)

58% (1992)

33% (1987)