75% (1989)

62% (1981)

69% (1986)

71% (1981)

67% (1983)

70% (1984)

65% (1989)

73% (1987)

61% (1987)

59% (1990)

69% (1986)

67% (1991)

58% (1982)

68% (1990)

65% (1984)

62% (1986)

64% (1982)

72% (1989)

54% (1988)

61% (1986)