Average relative D-meson yields in $|y_{\rm lab}|< 0.5$ as a function of (a) the relative charged-particle multiplicity at mid-rapidity $|\eta|< 1.0$, and (b) at backward-rapidity $2.8 < \eta < 5.1$ (including also $-3.7 < \eta < -1.7$ in pp data) for $2< \pt< 4 \gevc$ The relative yields are presented in the top panels with their statistical (vertical bars) and systematic (boxes) uncertainties, apart from the uncertainty on the B feed-down fraction, which is drawn separately in the bottom panels The positions of the points on the abscissa are the average values of $(\dNdEta) \big/ \langle \dNdEta \rangle$ or $\Nvzero \big/ \langle \Nvzero \rangle$. A diagonal (dashed) line is also shown to guide the eye