\begin{center}
\begin{tabular}{@{}rrrrr@{}}
\toprule
$a$ & Passes & Patterned gates & Grid sup error & Global upper bound \\
\midrule
0.200 & 41 & 123 & 0.200136 & 1.202612 \\
0.100 & 320 & 960 & 0.105215 & 0.671175 \\
0.050 & 2,560 & 7,680 & 0.053299 & 0.357692 \\
0.025 & 20,480 & 61,440 & 0.026709 & 0.185125 \\
\bottomrule
\end{tabular}
\end{center}