Histogram of the Be fraction of stars in SMC cluster NGC 330 (Milone et al. 2018) as a function of apparent magnitude in the Hubble Space Telescope Wide-field Camera 3 filter F814W, m_F814W plotted as white columns. It is assumed that Hα emitters are Be stars. Over plotted as coloured lines are our model predictions in the same magnitude bins for various minimum rotation rates to be counted as a Be star, as given in the legend.