Cumulative mass yields (thin dashed lines) and (thin solid lines) as a function of the maximum initial mass for the models resulting in 0.1 M_⊙ of ⁵⁶Ni. The masses are normalised on the total ⁵⁹Co mass. Thick solid line shows f_Ni, also as a function of the maximum initial mass. Green points in the upper panel indicate the f_Ni obtained from model calculations of Woosley & Weaver (1995) in the mass domain between 11 and 25 M_⊙, which is in the mass domain that was considered in the work by Wiedenbeck et al. (1999).