**2. GRB Light Curves**

The analysed GRB samples include bursts detected by the BATSE instrument on the *Compton Gamma-Ray Observatory* [77], the Burst Alert Telescope (BAT) on the *Neil Gehrels Swift Observatory* (hereafter *Swift*/BAT; Gehrels et al. [78]) and the Gamma-ray Burst Monitor (GBM) on the *Fermi Gamma-ray Space Telescope*(hereafter *Fermi*/GBM; Meegan et al. [79]).
