\begin{table}%t1
\caption{\label{tab1}Pearson correlation coefficients between $D_{\rm 2d}$ and $D_{\rm 3d}$ for the potential and the NLFF cases.}                  
%\centering
\par
\begin{tabular}{c c c c}        
\hline\hline             
Extrapolation  & Used 3d     & Correlation & Corresponding   \\    
Method & criterion  & with $D_{\rm 2d}$& Probability   \\   
\hline                        
   Potential & $G_{\rm av}$ & 0.719 & 99\%\\
   NLFF with preprocessing & $G_{\rm av}$ & --0.154 & 65\%\\
   NLFF with preprocessing & $C_{n}$ & 0.251 & 87\%\\
\hline                                   
\end{tabular}
\end{table}