Number ratios of different quantities as a function of metallicity, as obtained from our model population. Top: number ratio of Type Ib SNe to Type Ic SNe, ⟨N_Ic/N_Ib⟩, compared to the observed ratio of Type Ib SNe to Type Ic SNe ⟨N_Ic/N_Ib⟩_obs and of Type Ib SNe plus Type IIb to Type Ic SNe ⟨N_Ic/(N_Ib + N_IIb)⟩_obs in the local Universe, inferred from the relative rates of Shivvers et al. (2017). Bottom: Number ratio of BHs to SN explosions ⟨N_BH/N_SN⟩ and number ratio of Type Ib SNe with WR progenitors to Type Ib SNe with transparent-wind helium star progenitors ⟨N_{Ib from WR}/N_{Ib from TWHS}⟩.