Mean abundance ratios of sample stars in age bins of 20 stars as a function of the average age of the stars in those bins. The grey areas represent the ±1σ errors on the mean abundance values. The upper row and the upper middle row provide the mean abundances of the Mg, Al, and Si α elements; and the Ti, Cu, and Zn iron-peak elements, respectively. The lower middle row and the lower row show the mean abundances of the Sr, Y, and Zr light; and the Ba, Ce, and Nd heavy s-process elements, respectively. The circles indicate the corresponding element abundances in the Sun. The dashed lines represent best-fit simulations of the mean abundance ratios with a chemical evolution model of a metal-rich gaseous disc with low initial surface density experiencing an infall of pristine gas (see Model A in Table 1). The continuous lines represent the best-fit simulations of the mean abundance ratios with a chemical evolution model of a metal-rich gaseous disc with a moderate initial surface density experiencing an infall of pristine gas (see Model B in Table 1).