Daily latitudinal shift (top row) and longitudinal shift (bottom row) of the leading part (right column, plotted with dots) and following part (left column, depicted by circles) versus AEP. The shifts are averaged over each 10% bin of AEP, the error bars mean the standard error. Positive and negative values of latitudinal shifts mean poleward/equatorward, and that of the longitudinal shifts concern forward and backward motion of sunspot groups.