Probability distributions of magnification amplitude, Δm. The black histogram is generated from Δm_sim in the simulated light curves, with the median (dashed line), along with the 84th and 16th percentile indicated as grey shaded areas. The red vertical lines, Δm_obs, are measured in the observed light curves and given in Table 2. We also display the quadratic sum of the photometric uncertainties as a red shaded line.