60% (1984)

69% (1983)

50% (1984)

0% (1985)

65% (1984)

61% (1982)

40% (1985)

74% (1986)

56% (1983)

60% (1987)

58% (1982)

70% (1984)

75% (1988)

55% (1986)

50% (1985)

35% (1981)

80% (1988)