\begin{table}%t1
\caption{Summary of observation dates, array configurations and numbers of sources observed.
\label{tbl:observation_dates}}
%\centerline
 {\begin{tabular}{ccccc}
\hline
\hline
Dates& Obs. 	& Arr.	& \multicolumn{2}{c}{Fields Observed} \\
	& time (h)  & config.&   RMS   & Additional$^a$	\\
\hline
25, 28th/08/2002 & 14		& 6C	&  37  &22\\
19--22nd/07/2003 & 48		& 6D	&  152 &156 \\
15--19th/05/2004 & 60		& 6C	&  309 &1\\
24--30th/11/2004 & 72		& 6D	&  304 &7\\
\hline
\end{tabular}}
\par
\smallskip
$^a$ Observations towards sources that passed our initial colour selection criteria but were later excluded for various reasons (see Sect.~\ref{sect:additional_obs} for details).
\par
\end{table}