69% (1981)

72% (1988)

68% (1980)

60% (1978)

68% (1976)

61% (1973)

58% (1980)

59% (1986)

60% (1986)

49% (1982)

62% (1974)

64% (1974)

72% (1981)

65% (1980)

47% (1979)

64% (1977)

55% (1987)

100% (1990)

33% (1975)

53% (1981)