63% (1986)

70% (1988)

69% (1989)

63% (1985)

61% (1986)

46% (1971)

56% (1986)

69% (1987)

58% (1987)

65% (1987)

46% (1987)

63% (1982)

60% (1986)

59% (1984)

58% (1985)

57% (1989)

63% (1990)

47% (1989)

54% (1990)

62% (1985)