72% (1988)

69% (1981)

67% (1980)

59% (1986)

72% (1981)

61% (1973)

59% (1980)

59% (1986)

47% (1979)

65% (1986)

60% (1978)

65% (1977)

62% (1974)

68% (1976)

64% (1974)

50% (1979)

64% (1980)

55% (1979)

52% (1989)

68% (1980)