\documentclass[12pt,a4paper]{article}
\begin{document}
\begin{table}[ht]
\begin{center}
\caption{All statistics are based on contigs of size $\geq$ 100 bp, unless otherwise noted (e.g., "\# contigs ($\geq$ 0 bp)" and "Total length ($\geq$ 0 bp)" include all contigs).}
\begin{tabular}{|l*{12}{|r}|}
\hline
Assemblies & MG1\_ets & MG1\_sjw & MG2\_ets & MG2\_sjw & MG3\_ets & MG3\_sjw & MG5\_ets & MG5\_sjw & MG6\_ets & MG6\_sjw & MG7\_ets & MG7\_sjw \\ \hline
Flavobacterium\_sp.\_SCGC\_AAA160\_P02 & 37.90 & 62.62 & 32.88 & 57.27 & 34.14 & 64.01 & 24.65 & 37.18 & 31.73 & 58.60 & 30.22 & 58.48 \\ \hline
Planktomarina\_temperata\_RCA23 & 12.66 & 21.90 & 12.29 & 14.92 & 12.96 & 15.52 & 9.70 & 10.61 & 13.66 & 18.07 & 9.64 & 16.57 \\ \hline
Rhodobacterales\_bacterium\_HTCC2255 & 14.00 & 25.99 & 11.14 & 20.81 & 11.19 & 20.81 & 10.83 & 20.59 & 12.78 & 24.88 & 12.05 & 23.14 \\ \hline
alpha\_proteobacterium\_SCGC\_AAA076\_C03 & 15.38 & 22.59 & 13.09 & 22.81 & 11.83 & 18.78 & 10.56 & 17.76 & 13.69 & 25.96 & 12.67 & 22.04 \\ \hline
marine\_gamma\_proteobacterium\_HTCC2080 & 14.40 & 16.70 & 12.27 & 14.05 & 9.39 & 11.20 & 0.00 & 61.56 & 12.06 & 18.84 & 11.45 & 18.86 \\ \hline
\end{tabular}
\end{center}
\end{table}
\end{document}
