Previously published estimates of ﹩{f}_{\mathrm{ov}}﹩ from Paper II and Paper III (37 binary systems) as a function of stellar mass, along with the upper limit (dashed line) expected from the criterion of Roxburgh (1978) for stars with small convective cores (see also the bottom panel of Figure 12). The solid line, taken from Paper III, is an approximate representation of the observed trend drawn to guide the eye.