Number and density distributions of SNe Ia with respect to redshift. The parent sample of simulated SNe Ia is shown in blue, those detected in photometry are shown in green and those successfully typed with spectroscopy are shown in red. Top panel: number of simulated ZTF type-Ia supernova versus redshift per bins of Δz_obs = 0.005, averaged over 27 independent mock realizations of a 6-year program. Bottom panel: comoving number density of SNe Ia versus redshift, calculated assuming the fiducial cosmology from Table 1.