\begin{table}%t1
\caption{\label{op}Column densities of ortho and para water in the foreground material. }
 \vspace{-3mm}
%\centering
\par
\begin{tabular}{c c c c c}        
\hline\hline  
\noalign{\smallskip}             
Comp. &  vel. range &  $N$(o-H$_2$O) & $N$(p-H$_2$O) & o/p ratio \\  
& kms$^{-1}$ & $10^{12}$~[cm$^{-2}$] &  $10^{12}$~[cm$^{-2}$]  & \\
\hline                        
   --6.3 & --6 to --2 & $31.4\pm9.4$ & $19.3\pm7.8$  & $1.6\pm0.8$ \\     
   --0.3 & --2 to 1  &  $14.2\pm3.1$ & $8.8\pm2.0$ & $1.6\pm0.5$ \\
   +6.2 &  5 to 8  & $17.8\pm5.8$  & $9.6\pm4.3$  & $1.8\pm1.0$ \\
\hline                                
\end{tabular} 
\vspace{-3mm}
\end{table}