Comparison between the stability index a based on the LMWN and (top left panel) the flux at 8.4 GHz, (top right panel) the B magnitude, (bottom left panel) the radio-to-optical distance deduced from the comparison between the ICRF2 positions and Gaia DR1, and (bottom right panel) the redshift. The horizontal bars indicate the second (from the left extremity) and the third (to the right extremity) quartiles. The larger disk indicates the median.