Time dependence of the outflow velocity v_out (top), ionization parameter ξ (middle), and column density N_H (bottom). For each panel we show the values of Abs. 1 (red stars), Abs. 2 (green triangles), and Abs. 3 (blue squares). Lower limits on N_H were marked with an arrow. Horizontal lines with shaded bands represent the median values and the corresponding median absolute deviations.