Number of galaxies that reside in a dark halo (upper panels) and distributions of mass ratio between galaxies and dark halos that host them (lower panels) at redshifts ﹩z=0﹩ and 2. In lower panels, solid lines indicate the mean baryon fraction (﹩\Omega _{b}/ \Omega _{0}﹩) and dashed lines indicate the resolution limit constrained by the minimum mass of galaxies in their definition (see § 2.2).