\begin{table*}[ht]
\centering
\caption{Extrapolated $1\sigma$ uncertainties on $H_0$ from GW memory, scaled to the expected number of detections via $\sigma(N)=\sigma(N_\mathrm{det})\sqrt{N_\mathrm{det}/N}$. Each cell shows the mean $\pm$ population scatter $\sigma_\mathrm{pop}$ (astrophysical variance across event realisations), with the error on the mean $\sigma_\mathrm{err}$ (Monte Carlo accuracy) in parentheses.}
\label{tab:sigma_H0_combined}
\begin{tabular}{lrrrrcc}
\toprule
Detector & $T_\mathrm{obs}$ [s] & $f_\mathrm{min}$ [Hz] & $M_\mathrm{max}\ [M_\odot]$ & Approx. & $\sigma_{H_0}(N_\mathrm{lo})$ [$\pm\,\sigma_\mathrm{pop}$ ($\sigma_\mathrm{err}$)] [km\,s$^{-1}$\,Mpc$^{-1}$] & $\sigma_{H_0}(N_\mathrm{hi})$ [$\pm\,\sigma_\mathrm{pop}$ ($\sigma_\mathrm{err}$)] [km\,s$^{-1}$\,Mpc$^{-1}$] \\
\midrule
\multicolumn{7}{l}{\textit{ET+CE}} \\
 & 8 & 20 & 100 & MWM & 1.54 $\pm$ 0.30 (0.09) & 0.22 $\pm$ 0.04 (0.01) \\
\bottomrule
\end{tabular}
\end{table*}