38% (1985)

57% (1992)

37% (1995)

53% (1992)

68% (1989)

60% (1983)

38% (1980)

47% (1982)

47% (1981)

53% (1978)

22% (1988)

52% (1986)

62% (1977)

33% (1979)

10% (1998)