Top: Γ distribution of all sources (empty histogram), and obscured sources (N_H > 10²² cm⁻², black histogram). Bottom: Γ distribution of all unambiguous AGN, defined by L_X > 10⁴² erg s⁻¹ (empty histogram), and obscured AGN (N_H > 10²² cm⁻², black histogram). The Γ presented is that from the primary power law only.