\begin{table}%t2
  \caption {\label{tab:hc15n}Properties of the average \hcfifn\jone\ profiles and
    average fractional abundance towards the observed cores (main beam
    temperature scale).}
%\centerline
 {\begin{tabular}{l r c c c c c c}\hline\hline\noalign{\smallskip}
    Source & $\aver{\tmb}$ & $\aver{W}$ & $\aver{v_0}$ & \aver{{\it FWHM}} & 
    $\aver{N(\hcfifn)}$ & $\aver{N(\hh)}_{20\arcsec}$\tablefootmark{b} & $\aver{N}/\aver{2N(\hh)}$\tablefootmark{c} \\
    \smallskip\\
    & mK & m\kkms &\kms & \kms & \tdix{10}~\cc & \tdix{22}~\cc & $\times\dix{-12}$ \smallskip\\\hline
    L~183 & 125 $\pm$ 15 & 47 $\pm$ 4 &2.49 & 0.35 $\pm$ 0.04 & 8.9 $\pm$ 0.8 & 5.6 & 0.8\\%$\pm$ 0.21\\
    L~1544\tablefootmark{a} & 170 $\pm$ 12 & 85 $\pm$ 5 &7.20 & 0.48 $\pm$ 0.05 &16.1 $\pm$ 1.0 & 4.3 & 1.9\\%$\pm$ 0.44\\
    Oph~D & 102 $\pm$ 15 & 47 $\pm$ 6 &3.44 & 0.43 $\pm$ 0.08 & 8.9 $\pm$ 1.1 & 5.6 & 0.8\\%$\pm$ 0.25\\
    L~1517B & 82 $\pm$ 15 & 29 $\pm$ 3 &5.69 & 0.33 $\pm$ 0.04 & 5.5 $\pm$ 0.6 & 2.0 & 1.4\\%$\pm$ 0.40\\
    L~310 & 20 $\pm$ 10 & 21 $\pm$ 3 &6.69 & 0.98 $\pm$ 0.16 & 4.0 $\pm$ 0.6 & 0.8 & 2.5\\%$\pm$     \hline
    \hline
  \end{tabular}}
\par
      \tablefoot {
   \tablefoottext{a} {Using a two-component Gaussian fit. The {\it FWHM} is taken to be the
    equivalent linewidth, in this case; $v_0=7.2$~\kms\ is adopted
    from \cite{hilyblant2008cn}.}
     \tablefoottext{b} {Column density of \hh\ derived from the dust emission
    smoothed to 20\arcsec, assuming $\tdust=8$~K (see
    Table~\ref{tab:cores}). The total (statistical and systematic)
    uncertainty is~30\%.}
   \tablefoottext{c}{The uncertainty is typically~40\%.}}
\par
\end{table}