\begin{table}%t3
\caption{\label{table:aper_corr}Statistics of the average aperture corrections and image quality over nights when both science and standards were observed.}
\small%\centerline
 {
\begin{tabular}{cc cc cc}
\hline
\hline
   & \multicolumn{2}{c}{Science}  & \multicolumn{2}{c}{Standards}  & \multirow{2}{*}{$\rho_{\rm sci,std}$} \\
\cline{2-5}
 & average & rms & average & rms & \\
\hline 
AC & 2.34\% & 0.55\% & 2.10\% & 0.59\%  & 0.66 \\
IQ & 0.89\arcsec & 0.2\arcsec & 0.99\arcsec & 0.30\arcsec  & 0.42 \\
\hline
\end{tabular}}
\medskip
The correlation coefficients (last column) are computed for data taken over the same night in the same band.
\end{table}