%\noindent
\begin{tabular}{||l||c|c|c||c|c|c||c|c|c||c|c|c||}
\hline
 & 
\multicolumn{3}{c||}{$n=9275$} &
\multicolumn{3}{c||}{$n=9275$} &
\multicolumn{3}{c||}{$n=20284$} &
\multicolumn{3}{c||}{$n=20284$} \\
Num & 
\multicolumn{3}{c||}{$M=84$} &
\multicolumn{3}{c||}{$M=1234$} &
\multicolumn{3}{c||}{$M=66$} &
\multicolumn{3}{c||}{$M=2214$} \\
\cline{2-13}
proc &
D &I+G&Tot&
D &I+G&Tot&
D &I+G&Tot&
D &I+G&Tot\cr
\hline
1 &
 47.7 &  0.21 &  68.0 &
 6.1 & 4.83 & 13.5 &
 142.3 &  0.18 & 201.1 &
 40.6 & 46.49& 104.1 \cr
2 &
22.5 & 0.18 & 33.2 &
 3.0 &  4.82 &  9.6 &
68.4 &  0.18 &  100.3 &
 19.8 & 46.05 & 75.1 \cr
4 &
10.8 &  0.17 &  16.5 &
 1.5 &  4.82 &  7.4 &
 30.7 & 0.16 &  47.0 &
 9.7 & 46.08 & 64.1 \cr
8 &
 5.0 &  0.17 &  9.2 &
 0.7 & 4.80 & 6.6 &
 14.3 & 0.16 &  23.3 &
4.5 & 46.08 &  58.3 \cr
\hline
\end{tabular}