65% (1987)

71% (1988)

56% (1986)

69% (1987)

63% (1986)

46% (1987)

68% (1989)

62% (1990)

63% (1985)

63% (1982)

62% (1986)

59% (1986)

54% (1990)

54% (1981)

55% (1987)

59% (1984)

58% (1987)

69% (1985)

66% (1982)

61% (1988)