The decline parameter Δm₁₅ computed for the bolometric light curves versus the late-time linear decay slope (top panel) and the peak bolometric magnitude (bottom panel). A possible correlation is observed in the first case, which might be explained by a range of values of the E_K/M_ej ratio (see Sect. 5). SNe IIb, Ib, Ic, and Ic-BL are represented in green, blue, red, and magenta, respectively.