Results for the SFE histories obtained using the chemical and SFH of each galaxy. In the upper left panel, we show the relation between stellar masses and median SFEs and in the upper right panel the relation between stellar masses and the slope of the SFE histories. In both of these panels the color corresponds to the sSFRs. In the bottom left panel, we show the relation between the stellar masses and the effective radii with the median SFEs shown in color. The blue line corresponds to a cubic fit to the M_⋆–R_e relation. In the bottom right panel, we show the relation between the ratio of R_e to the value of the cubic fit shown in the left panel and the median SFE, with the slope of the SFE histories shown in color. The contours in each panel enclose 35%, 65% and 95% of the distribution respectively. The thicker points shown in each panel correspond to the median values of the Y-axis quantity within 0.5 dex wide bins in the physical quantity of the X-axis selected as indicated in the legend for each color, with the error bars marking the 25th and 75th percentiles.