R_V estimations in the vicinity of SNe versus HG stellar age (expressed in gigayears). The legend presents the fitting parameters following y = mx + b, as well as the correlation, corr, between the properties; the mean normalized residuals of the fit, Nresd; and the coefficient of determination of the fit, R². The dashed blue line presents the linear fit, while the dotted red lines provide the lσ uncertainty interval of the fit.