Distribution of the change in average radial random kinetic energy and the specific angular momentum for the total (thin+thick) disc within the bar region (see Eqs. (9) and (10)) for all models considered here. Left panels: evolution for the rthickS models, and the middle and right panels: evolution for the rthickE and rthickG models, respectively. The points are colour-coded by the maximum value of the bar strength (S​_bar, max). The increasing size of the points denotes a higher thick-disc fraction (f_thick = 0.1 − 1).