Decay time vs. rise time for the sample of late-time flares (blue squares) compared with the early-time flare sample (red stars). The best linear fitting for the two samples is t_d = (−0.1 ± 0.6) + (2.15 ± 0.04)   t_r (pink line). Grey area: . Inset: distribution of the ratio t_r/t_d of late-time flares (blue rectangles) compared with the early-time flare one (red rectangles). The two distributions are centred on a similar value (median 0.52 with σ = 0.23 for the late-time flares and median 0.49 with σ = 0.26 for the early-time flares).