Evolution of Fe ii 5018 Å pEWs with time, as presented in Fig. 3, separated into 4 panels splitting the sample by their Fe ii 5018 Å pEWs at 50 d. The distributions go from low pEW in panel a) through to the highest pEW sample in panel d). The overall sample is presented in blue, while the “Gold” sample discussed later is plotted in magenta. (Errors are not plotted to enable better visualisation of the trends.)