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\begin{table}
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{\bfseries\strut Bias statistics}

\begin{tabular}{cccc}
    \toprule
    \textbf{Bias} & 
    \begin{tabular}{@{}c@{}}\textbf{rewarded}\end{tabular} & 
    \begin{tabular}{@{}c@{}}\textbf{unrewarded}\end{tabular} \\
    \midrule
    $P_{\rm{SF}}$    & $0.77 \pm 0.03$ & $0.78 \pm 0.02$ \\
    $P_{\rm{SA}}$    & $0.72 \pm 0.02$ & $0.71 \pm 0.02$ \\
    $P_{\rm{BF}}$    & $0.82 \pm 0.03$ & $0.81 \pm 0.03$ \\
    $P_{\rm{BS}}$    & $0.64 \pm 0.02$ & $0.63 \pm 0.02$ \\
    \bottomrule
\end{tabular}
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\end{table}
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