60% (1986)

52% (1984)

60% (1986)

62% (1983)

61% (1984)

54% (1985)

73% (1988)

58% (1985)

63% (1983)

65% (1978)

61% (1982)

55% (1987)

55% (1986)

63% (1979)

62% (1984)

55% (1986)

28% (1983)

51% (1976)

55% (1989)

54% (1983)