When you examine the data however, you find that the strings of comets on these plots have identical eccentricities. The lowest string on the above plot are comets all with eccentricity of 0.999, while the string above it have eccentricities of 0.998, and so forth. The precision of the eccentricities being 'granular' to the third decimal place causes artificial clumpings on the lower part of this graph.