For each row, the left and right cumulative blue histograms of 10⁶ Monte Carlo realizations of Galactic populations of CR sources are displayed in the left and right panels, respectively, whereas the pdf P(Ψ) stands in the middle. The MED propagation model is used without taking into account convection, diffusive reacceleration and spallations. From top to bottom, the CR kinetic energy has been set equal to 100 GeV, 1 TeV, and 10 TeV. The solid green line indicates the theoretical prediction for the 2D model of the Galactic magnetic halo, whereas the dashed red curve corresponds to the 3D case. The residuals between theory and simulations are displayed below each histogram with their 1σ Poissonian error.