74% (1987)

67% (1988)

53% (1990)

53% (1987)

45% (1989)

62% (1988)

46% (1991)

61% (1990)

58% (1989)

59% (1990)

59% (1989)

56% (1988)

62% (1989)

43% (1992)

54% (1990)

49% (1988)

55% (1989)

61% (1988)

49% (1989)

45% (1988)