\begin{table}%t1
\caption{\label{table:1}Dust mass loss rates and grain lifetimes, $t_{\rm g}$.}
%\centering
\par
\begin{tabular}{c c c c c c}       
\hline\hline \noalign{\smallskip}               
NGC \T & $\dot{M}_{\rm d}/L_{\nu}(\rm K)$\tablefootmark{\dagger} &$\dot{M}_{\rm d}/M$\tablefootmark{\ddagger} & $\dot{M}_{\rm d}(\rm beam)$& $t_{\rm g}$\tablefootmark{\ast} \\
     \B & $\frac{M_{\odot}~{\rm yr}^{-1}}{\rm 10^{26}~W~Hz^{-1}}$ &$\frac{M_{\odot}~{\rm yr}^{-1}}{10^{12}~M_{\odot}}$ &  $10^{-4}~M_{\odot}~{\rm yr}^{-1}$ & $10^{6}\;\rm yr$ \\
\hline
4371 & 3.80 & 0.00855 & 1.0  & 86\\
4442 & 3.48 & 0.00712 & 1.7  & 51\\
4473 & 3.57 & 0.00742 & 1.9  & 46\\
4474 & 3.71 & 0.00806 & 0.59 &150\\
4551 & 2.61 & 0.00468 & 0.36 &240\\
4564 & 4.28 & 0.00959 & 1.3  & 65\\
\hline                                  
\end{tabular}
\tablefoot{\tablefoottext{\ast}{For an assumed dust temperature of 30~K.} \tablefoottext{\dagger}{The specific dust mass-loss rate per unit $K$-band luminosity.} \tablefoottext{\ddagger}{The mass loss per $10^{12}~M_{\odot}$ of galaxy mass. A dust mass opacity coefficient suitable for amorphous silicate grains has been used.}}
\end{table}