68% (1987)

57% (1986)

55% (1987)

58% (1986)

63% (1986)

53% (1987)

57% (1987)

58% (1984)

63% (1984)

61% (1984)

64% (1987)

62% (1985)

60% (1986)

59% (1985)

66% (1985)

52% (1985)

56% (1985)

54% (1986)

57% (1985)

61% (1985)