\begin{table}%T8
      \caption{\label{tab:line-ratios}Line intensity ratios.}
         \small%\centerline
{
         \begin{tabular}{lcccc}
            \hline\hline
            \noalign{\smallskip}
            Galaxy & CO~$\frac{2{-}1}{1{-}0}$ & CN~$\frac{2{-}1}{1{-}0}$ & HCN~$\frac{3{-}2}{1{-}0}$ &
            HNC~$\frac{3{-}2}{1{-}0}$\\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
		NGC~3079 & 0.77~$\pm$~0.20 & 0.48~$\pm$~0.15 & 0.18~$\pm$~0.06 & 0.25~$\pm$~0.12 \\
		NGC~1068 & 0.81~$\pm$~0.21$^{a}$ & 0.19~$\pm$~0.05 & 0.47~$\pm$~0.14 & 0.15~$\pm$~0.05 \\
		NGC~2623 & $^{b}$ & -- & -- & 0.36~$\pm$~0.15 \\
		NGC~1365 & 0.84~$\pm$~0.12$^{c}$ & 0.44~$\pm$~0.12 & 0.42~$\pm$~0.12 & -- \\
		NGC~7469 & 0.97~$\pm$~0.28 & -- & -- & $\la$$0.20$ \\
            \hline
         \end{tabular}}
          \smallskip
\begin{list}{}{}
\item[$^{{a}}$] For NGC~1068 we corrected the JCMT CO~$J=2{-}1$ observations to the beam size
of the SEST CO~$J=1{-}0$~line, applying the factor 20/44, the ratio between the respective beams. With this, the
beam dilution effect is cancelled in both transition lines.
\item[$^{{b}}$] See Casoli et~al. (\cite{casoli88}).
\item[$^{{c}}$] For NGC~1365 we also corrected the CO~$J=2{-}1$ observations to the beam size
of the CO~$J=1{-}0$~line, applying the factor 25/44 between the respective SEST beams. 
The ratio given above is slightly higher than the one reported by Sandqvist \etal~(\cite{sandqvist95}).
\end{list}
\end{table}