\begin{table}%t2
\caption{Subsamples of Main-Sequence stars (classes~V, IV--V and~IV):  the mean radii~${\overline R}/R_\odot$ and the mean masses~${\overline\mathscr{M}}/\ensuremath{\mathscr{M}_\odot}$ are derived from  \citet{HasHee81}, as well as the relative variation of the radius~$\Delta R$ and of the mass~$\Delta\mathscr{M}$ along the interval of spectral type. For each subsample, the number of stars is given.}
\label{subsamples}
%\centering
\small
    \begin{tabular}{cccccc}
\hline
\hline
 %&&&&& \\[-8pt]
Spec. types & ${\overline R}/R_\odot$ & $\Delta R$ (\%) & ${\overline\mathscr{M}}/\ensuremath{\mathscr{M}_\odot}$ & $\Delta\mathscr{M}$ (\%) &\# stars \\
\hline
       B9     & $1.95$ &      --    & $2.34$ &      --    & $198$ \\
       A0--A1 & $1.79$ & $\pm  0.8$ & $2.04$ & $\pm  1.5$ & $397$ \\
       A2--A3 & $1.70$ & $\pm  1.2$ & $1.90$ & $\pm  2.1$ & $377$ \\
       A4--A6 & $1.60$ & $\pm  2.5$ & $1.73$ & $\pm  3.8$ & $182$ \\
       A7--A9 & $1.48$ & $\pm  2.7$ & $1.52$ & $\pm  4.3$ & $190$ \\
       F0--F2 & $1.37$ & $\pm  2.2$ & $1.37$ & $\pm  2.2$ & $197$ \\
\hline
    \end{tabular}
\end{table}