Per-trigger nuclear modification factor ($I_{\rm{AA}}$) of NS (left) and AS (right) associated yields, for electrons from heavy-flavor hadron decays in the interval $4 \pt^{\rm{e}} 12$ \GeVc as a function of $\pt^{\rm{assoc}}$ in Pb--Pb collisions of centrality classes 0--10\% and 30--50\%. The statistical (systematic) uncertainties are shown as vertical lines (empty boxes). In some $\pt^{\rm{assoc}}$ intervals the AS yield is consistent with zero within one standard deviation of total uncertainty. For those intervals, upper limits on the $I_{\rm{AA}}$ for 68\% and 95\% confidence levels are shown with arrows and boxes, respectively.