Average density of UHECR sources in a sphere of radius D₀ normalized to the case of a homogeneous Universe, as function of that radius, for 300 different realizations of a UHECR source distribution randomly drawn from the mother catalog (see text) with an overall density of 10⁻³ Mpc⁻³ (red) or 10⁻⁴ Mpc⁻³ (blue). The thick red line shows the average overdensity for 300 realizations (thus close to that of the mother catalog itself), while the shaded area shows the spread around this average, and contains 90% of the realizations (excluding the 5% most overdense and the 5% most underdense realizations).