\begin{table}%t7
\center
\caption {Distribution of grades per passband. The table gives: in
Col.~1 the passband; in Col.~2 the ESO filter number; in Col.~3 the
number of images; in Cols.~4--7 the ratio of images in a given grade to
the total number of images taken with that filter.}
\label {tab:grade-distribution}\small
\begin{tabular}{ccccccc}
\hline\hline
Passband & Filter & \# reduced  & A & B & C & D \\
\hline
$U$&\#877&97&0.22&0.69&0.09&0.0\\
$U$&\#841&22&0.05&0.91&0.00&0.05\\
$B$&\#842&44&0.82&0.02&0.02&0.14\\
$V$&\#843&41&0.73&0.02&0.1&0.15\\
$R$&\#844&48&0.77&0.19&0.04&0.0\\
$I$&\#879&8&0.63&0.25&0.13&0.0\\
$I$&\#845&70&0.17&0.3&0.34&0.19\\
%$I$&\#854&1&0.0&0.0&0.0&1.0\\
\hline
\end{tabular}
\end{table}