Left panel: distributions of the change in radius R_f − R_i as a functionof R_i for different time intervals in the thin disc. Right panel: distributions of the change in guiding radius as a functionof for different time intervals in the thin disc. On each panel, shaded regions show the values spanned by the resonances radii (blue for ILR, orange for corotation and green for OLR) during the time interval, and the thick vertical orange line shows the average of the values of the corotation radius at the beginning and end of the time interval.