\begin{table}%t4
\caption{\label{tab4}Results of LVG radiative transfer calculations for representative observed values (see Table~\ref{tab2}).}  
\small%\centerline
 {
\begin{tabular}{lllllllll}
\hline\hline
&&&&&&&& \\[-8pt]
   & $T_{\rm peak}$  & $N({\rm CO})/\Delta v$ $^a$ & $\Delta v$ & $N({\rm CO})$ &
$T_k$ range & $n_{\HH}$ range $^b$ & $P_{\rm th}/k$ range $^b$ & $X({\rm CO})$ range $^b$\\ 
  & K & \cq/\kms\ & \kms\ & \cq\ & K  &\cc\ & K \cc\  & $\times 10^{-5}$   \\ 
\hline
&&&&&&&& \\[-8pt]
brightest & 4 & 3--$4 \times 10^{15}$ & 0.4 & 1.2--$1.6 \times 10^{15}$ 
& 10--200 & $3\times 10^3$--250 & 3--$5 \times 10^4$ & 2--20\\
most common  & 1.2 &  $1.5 \times 10^{15}$ &  0.2 & $3 \times 10^{14}$ & 
10--140 & $8\times 10^3$--300 & 8--$4 \times 10^4$ & 0.16--4\\
weakest & 0.6 &$1.0 \times 10^{15}$ & 0.1 & $1.0 \times 10^{14}$ & 7--35 & 
$1\times 10^4$--800 & 7--$3 \times 10^4$ & 0.11--1.4 \\ 
\hline
\end{tabular}}
\medskip
$^a$~Assuming $R(2{-}1/1{-}0)=0.7\pm 0.1$;
$^b$~the LHS (resp.~RHS) values correspond to the lowest (resp.~highest) gas temperature.
\end{table}