Left: histograms of the r-band timescales (t_r) above each 10% flux level relative to peak on the rise and decline. Right: the difference between successive 10% flux levels (Δt_r, namely, the inverted slope) on the rise and decline. The vertical lines in each panel mark the median (with its value on the top left) and P_15.9–P_84.1 and P_2.3–P_97.7 ranges. For each distribution, the temporal progression along the light curve is counterclockwise from the left-top to right-top panels. The inverted slope is an increasing function, i.e., the light-curve slope becomes shallower with respect to time.