Slopes of the error-weighted linear least squares fit to the datapoints of the lower panels of Figs. 8 and 9 as a function of the intermediate-age fractions ( f_10   G − f_1 G, upper panels;   f_10   G − f_5 G; middle panels), as well as a function of the mass-weighted mean age τ (lower panels), for Sculptor, Sextans, Carina, Fornax and Leo II. The red solid line corresponds to an error-weighted linear least squares fit to the data. The error bars correspond to the error of the coefficients of the fit to the datapoints of Figs. 8 and 9.