\begin{table}%t4
\caption{\label{tbl_NG_ice}Column density of ices and properties of YSOs.}
%\centering
\par
\begin{tabular}{ l c c c c c c c }
\hline\hline \noalign{\smallskip}
Number & $N$(H$_2$O)                 & $N$(CO$_2$)               & $N$(CO$_2$)/$N$(H$_2$O) & $N$(CO)                  & $N$(CO)/$N$(H$_2$O) & $EW$(Br$\alpha$) &  $L_{\rm tot}$ \\
   ~   & [10$^{17}$ cm$^{-2}$]     & [10$^{17}$ cm$^{-2}$]   & [$\%$]              & [10$^{17}$ cm$^{-2}$]  & [$\%$]              & [$\AA$]        &  [10$^3$ $\times$ $L_{\odot}$]   \\
\hline
ST1    & 22.5 $\pm$ 0.96           &   5.66 $\pm$ 0.64       & 25                  & 3.62 $\pm$ 0.93        & 16   & 100 $\pm$ 7     &  53 $\pm$ 18          \\
ST2    & 11.9 $\pm$ 1.0            &   3.64 $\pm$ 0.38       & 31                  & $<$0.5                 & $<$1 & 343 $\pm$ 12    &  182 $\pm$ 9          \\
ST3    & 38.1 $\pm$ 3.9            &   10.6 $\pm$ 1.6        & 28                  & 3.17 $\pm$ 0.92        & 8    & 21.3 $\pm$ 6.3  &  9.9 $\pm$ 1.0        \\
ST4    & 19.6 $\pm$ 0.83           &   7.41 $\pm$ 0.79       & 38                  & 2.71 $\pm$ 1.2         & 14   & 17.4 $\pm$ 5.1  &  4.0 $\pm$ 0.4        \\
ST5    & 26.4 $\pm$ 1.2            &   10.1 $\pm$ 0.79       & 39                  & 2.33 $\pm$ 0.82        & 9    & 119 $\pm$ 7     &  66 $\pm$ 12          \\
ST6    & 45.6 $\pm$ 16\tablefootmark{a}         &   17.1 $\pm$ 3.0        & 37                  & $<$13                  & ...  & 44.3 $\pm$ 21   &  6.6 $\pm$ 2.5        \\
ST7    & 27.8 $\pm$ 0.95           &   19.5 $\pm$ 1.8        & 70                  & $<$4                   & $<$14 & 15.8 $\pm$ 6.1 &  20 $\pm$ 5           \\
ST8    & 20.1 $\pm$ 1.2            &   9.34 $\pm$ 1.1        & 47                  & 2.60 $\pm$ 0.75        & 13   & 64.1 $\pm$ 6.2\tablefootmark{c}  &  46 $\pm$ 16\tablefootmark{d}  \\
ST9    & ...                       &   1.84 $\pm$ 0.17       & ...                 & $<$2                   & ...  & ...             &  54 $\pm$ 22          \\
ST10   & 39.8 $\pm$ 5.0            &   14.5 $\pm$ 2.1        & 36                  & 7.72 $\pm$ 1.5         & 19   & $<$10           &  32 $\pm$ 14          \\
ST11   & 8.9 $\pm$ 0.3             &   0.9 $\pm$ 0.23        & 10                  & $<$0.5                 & $<$1 & 116 $\pm$ 6.    &  338 $\pm$ 27         \\
ST12   & 2.34 $\pm$ 0.12           &   0.9 $\pm$ 0.15\tablefootmark{b}    & 39                  & ...                    & ...  & $<$7            &  23 $\pm$ 3\tablefootmark{d}       \\
\hline
\end{tabular}
\tablefoot {\tablefoottext{a}{Derived from low-resolution spectrum of \citet{ST}, but re-calculated after applying our own spectral reduction pipeline.}\\
\tablefoottext{b}{Derived by \citet{Oli09}.}\\
\tablefoottext{c}{Detection of a strong [OIII] emission line at 88~$\mu$m is reported by \citet{vanL10}.}\\
\tablefoottext{d}{Estimated luminosities 95 and 62~$L_{\odot}$ from \citet{vanL10}, on the basis of far-infrared data, for ST8 and ST10, respectively.}}
\end{table}