Disc fraction as a function of time from two evolving disc populations using the XPE profiles by P19 (solid blue line) and O12 (solid red line). For each model, 1000 simulations were performed, using different X-ray luminosities that were sampled randomly from the XLF of Taurus. The dotted lines show the corresponding median disc lifetimes of each distribution. The black dots show observed disc fractions compiled by Mamajek (2009). The simulated disc fractions were scaled to 86% in order to account for binary interactions (cf. Owen et al. 2011).