Models computed with the log-normal SFH and the four options for the DTD considered here (filled symbols) compared to data (empty symbols). Predictions obtained with different DTDs are plotted with different colours as labelled. For each DTD we adopt the best fitting value for k_Ia, namely k_Ia = (0.74,0.77,0.89 and 0.69) × 10⁻³ 1/M_⊙ for the SD, P.L., DD CLOSE and DD WIDE DTDs, respectively (see Appendix B). The symbols encoding of the observed rates is the same as in Fig. 8.