\begin{table}%t2
%\centering
\par
\caption{\label{DataSetTab}The various data sets used in the paper, referred to 
in the text by the labels presented in this table.}\vspace*{-1mm}
\begin{tabular}{*{8}{c}}
\hline \hline \noalign{\smallskip}
Label&   Period   &Runs& $T$(hours)    &Excess &  $\sigma$  & Section  & Additional criteria \\ 
   \hline
$D$   & 2005--2007 &165 & 69.7 & 67~654 & 237.4 &  \ref{SpecVar}, \ref{characteristic_time}  & --  \\
$D_{\rm QS}$   & 2005--2007 &115 & 48.1 & 12~287 &  60.5 &  \ref{QuiescentStateDistrib}, \ref{QuiescentStateSpectrum}, \ref{IntrinsicWidth}, \ref{characteristic_time} & July 2006 excluded \\
$D_{\rm QS-2005}$  &    2005    & 19 &  8.0 &  1816 &  22.6 &  \ref{QuiescentStateSpectrum} & -- \\
$D_{\rm QS-2006}$  &    2006    & 61 & 26.3 &  7472 &  48.4 &  \ref{QuiescentStateSpectrum} & July 2006 excluded \\
$D_{\rm QS-2007}$  &    2007    & 35 & 13.8 &  2999 &  28.6 &  \ref{QuiescentStateSpectrum} & -- \\
$D_{\rm JULY06}$ &July 2006& 50 & 21.6 & 55,367 & 281.8 &  \ref{SpecVar}, \ref{temporal_variab}, \ref{log_normal_process}, \ref{characteristic_time} & -- \\
$D_{\rm FLARES}$ &July 2006 (4 nights)&27& 11.8 & 46~036 & 284.1 &  \ref{SpecVar}, \ref{temporal_variab}, \ref{log_normal_process}, \ref{characteristic_time} & --\\
   \hline
\end{tabular}\vspace*{-2mm}
\tablefoot {Only runs with the full array of four telescopes in operation (202~runs over~210) and an energy threshold lower than 200~GeV (165~runs over~202) are considered. The corresponding period of the observations, the number of runs, the live-time~$T$ (hours), the number of $\gamma$~excess events and its significance~$\sigma$ are shown. The column $section$ indicates the sections of the paper in which each data set is discussed. Additional criteria for the data set definitions are indicated in the last column.}
\vspace*{-1mm}\end{table}