\begin{table}%t3
\caption{\label{table:2}Star counts in the CMD boxes defined in Fig.~\ref{rsg}. Box~A samples the upper MS, boxes~B, C, and D~samples SG~stars of blue, intermediate and red colors, respectively. $N_{\rm exp}$~is the number of stars expected in a given box from the field population, computed by
rescaling the observed counts in the WF2~field by the ratio of the sampled areas. The ratio between the area of the considered field (annulus) and the area of the WF2~field (used as representative of the field population) is reported in the last column.}             
%\centering
\small
\begin{tabular}{c c c c c c c c c c} 
\hline\hline       
Field & \multicolumn{2}{c}{Box {\bf A}} &\multicolumn{2}{c}{Box {\bf B}} & 
\multicolumn{2}{c}{Box {\bf C}} & \multicolumn{2}{c}{Box {\bf D}} & Area$_{\rm field}$/Area$_{\rm WF2}$\\ 
      & $N_{\rm obs}$ & $N_{\rm exp}$ & $N_{\rm obs}$ & $N_{\rm exp}$ & $N_{\rm obs}$ & $N_{\rm exp}$& $N_{\rm obs}$ & $N_{\rm exp}$ &\\
\hline                    
PC: 10 px $<r\le$ 160 px    & 68  & $4.8\pm0.6$ & 9 & $0.7\pm 0.2$ & 5 & $0.2\pm 0.1$ & 16 & $1.5\pm 0.3$ & 0.0708\\  
PC: 160 px $<r\le$ 330 px   & 27  &$15.7\pm1.9$ & 4 & $2.3\pm 0.7$ & 1 & $0.7\pm 0.4$ &  9 & $5.1\pm 1.1$ & 0.2314\\  
WF2: $r\le$ 300 px                & 68  &  ---        &10 & ---          & 3 & ---          & 22 & ---          & 1.0000\\  
\hline                  
\end{tabular}
\end{table}