67% (1977)

60% (1978)

38% (1972)

53% (1980)

58% (1981)

72% (1980)

65% (1970)

49% (1976)

57% (1979)

54% (1978)

55% (1983)

59% (1975)

57% (1980)

60% (2007)

52% (1988)

63% (1986)

69% (1977)

45% (1980)

57% (1981)

54% (1980)