Statistical properties of Stokes V amplitude asymmetry, δa. From left to right, the correlation of δa with the strength of the LOS magnetic field,  |B_LOS| , for all data (first plot) and the averaged δa for dark (upper curve), all (middle curve) and bright (lower curve) structures (second plot). The third plot shows the correlation between LOS velocity and δa for 200   G <  |B_LOS|  < 800 G, the fourth plot for  |B_LOS|  > 800 G.