\begin{table}%t12
\caption{\label{tab12}The group means for the parameters of the GCs of M~31.}
\small%\centering
\par
\begin{tabular}{cccc}
\hline\hline
Variables& Cluster 1& Cluster 2& Cluster 3\\
\hline No. of members&9&19&7\\
$\langle[{\rm Fe/H}]\rangle$&--0.43&--1.51&--1.41 \\
$\langle B-V\rangle$&1.06&0.76&0.73\\
$\langle c\rangle$&1.67&1.55&1.08\\
$\langle R_{\rm c}\rangle$(pc)&0.545&0.92&1.93\\
$\langle R_{\rm gc}$(kpc)&5.28&8.78&8.17\\
$\langle\mu_V\rangle$&16.28&16.01&16.56\\
$\langle v_{\rm rot}\rangle$ (km~s$^{-1}$)&52.87&31.16&51.90\\\hline
\end{tabular}
\end{table}