\begin{table}%t5
\caption{\label{galratio}Adopted velocity-integrated line ratios in galaxy centres.}
%\centerline
{
\begin{tabular}{l ccc ccc}
\hline\hline
Transitions          & Beam   & NGC~278       & NGC~660       & NGC~3628      & NGC~4631      & NGC~4666     \\
                     & ($'')$ &               &               &               &               &  
\\
\hline
$\co$ \\
(1--0)/(2--1)  & 21     & 0.89~$\pm$~0.16 & 1.19~$\pm$~0.17 & 1.40~$\pm$~0.28 & 1.72~$\pm$~0.26 & 1.42~$\pm$~0.21 \\
(2--1)/(2--1)  & 12/21  & 1.58~$\pm$~0.24 & 2.57~$\pm$~0.40 & 1.38~$\pm$~0.28 & 1.68~$\pm$~0.25 & 1.37~$\pm$~0.21 \\
(3--2)/(2--1)  & 21     & 0.79~$\pm$~0.13 & 0.69~$\pm$~0.11 & 0.62~$\pm$~0.12 & 0.66~$\pm$~0.10 & 0.69~$\pm$~0.10 \\
(3--2)/(2--1)  & 12     & 0.74~$\pm$~0.13 & 0.66~$\pm$~0.12 & 0.87~$\pm$~0.17 & 0.58~$\pm$~0.09 & 0.80~$\pm$~0.12 \\
(4--3)/(2--1)  & 21     & 0.56~$\pm$~0.08 & 0.66~$\pm$~0.11 & 0.65~$\pm$~0.13 &     ---       & 0.30~$\pm$~0.05 \\
(4--3)/(2--1)  & 12     & 0.54~$\pm$~0.10 & 0.49~$\pm$~0.09 & 0.74~$\pm$~0.15 & 0.46~$\pm$~0.07 & 0.36~$\pm$~0.05 \\
\hline 
$\co$/$\treizeco$ \\
(1--0)         & 21     &  8.4~$\pm$~1.3  & 15.7~$\pm$~2.0  & 12.2~$\pm$~1.8  & 13.0~$\pm$~2.0  &  8.5~$\pm$~1.3  \\
(2--1)         & 21     &  8.6~$\pm$~1.4  & 12.2~$\pm$~1.8  & 11.7~$\pm$~1.6  & 22.2~$\pm$~3.3  &  6.7~$\pm$~1.0  \\
(2--1)         & 12     &  9.6~$\pm$~1.5  & 18.8~$\pm$~2.8  & 13.2~$\pm$~1.9  & 11.4~$\pm$~1.6  &  6.3~$\pm$~1.0  \\
(3--2)         & 14     & 11.4~$\pm$~1.7  & 12.8~$\pm$~1.9  &  7.9~$\pm$~1.8  &      ---      & 11.3~$\pm$~1.7  \\
 \lbrack CI\rbrack/CO(2--1)) & 21     & 0.29~$\pm$~0.04 & 0.20~$\pm$~0.05 & 0.28~$\pm$~0.06 &      ---      &      ---       \\
\hline
\end{tabular}}
\end{table}