Distributions of the observational prevalence ratio r = n_BAL/n_Total as a function of the Eddington ratio for three M_• ranges, shown by solid black lines, compared to simulation data for the case without a torus. The metallicities of 1, 2.5, 5, and 10 are depicted in blue, red, magenta, and green, respectively. The solid lines in each case show the best exponential fit to the corresponding data.