Stellar metal yield ratios of stars with different mass and metallicity given by Kobayashi et al. (2006). The yields from Kobayashi et al. (2006) for massive stars are connected to the yields for low- and intermediate-mass stars as given by Marigo (2001). The yields for M_* >  40 M_⊙ are the same as the yields for M_* = 40 M_⊙ stars. The red shaded region with log₁₀(M_*, initial[M_⊙]) >  1.3073 indicates zero-metallicity stars with lifetimes shorter than 10 Myr, according to Yan et al. (2019).