Type-2 AGN fraction vs. torus covering factor f₂ for objects with ﹩{10}^{42}\lt {L}_{{\rm{X}}}\lt {10}^{43}﹩ (top), ﹩{10}^{43}\lt {L}_{{\rm{X}}}\lt {10}^{44}﹩ (middle), and ﹩{10}^{44}\lt {L}_{{\rm{X}}}\,\lt {10}^{45}\,\mathrm{erg}\,{{\rm{s}}}^{-1}﹩ (bottom). Filled circles are the observed type-2 AGN fractions in BUXS. Open squares are the best-fit models to the 1:1 relations (black solid lines) obtained by allowing a population of non-detected type-2 sources. The insets show the assumed f₂ distribution of these missed sources.