Notice that these percentage are the percentage of children with "elevated lead"., I'm making up numbers here but If we consider elevated to be anything more th

Notice that these percentage are the percentage of children with "elevated lead"., I'm making up numbers here but If we consider elevated to be anything more than X ug/L . first of all how was this X chosen? Secondly, if 6.7% of NY state children have (X + 0.01), this would be very different from 4.9% of children who have let's say ( X * 3 )