\begin{table}%t2
   %\centering
\par
      \caption{The properties of the cell and network brightenings due to Harra et~al. (\cite{Harra00}). \label{tab2}}
		 \begin{tabular}{llll}
            \hline\hline
            \noalign{\smallskip}
	Property & Network & Cell & Total \\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
	Global frequency & 2177 s$^{-1}$ & 2635 s$^{-1}$ & 2292 s$^{-1}$ \\
	Mean O V enhancement & 10\% & 11\% & 11\% \\
	Mean lifetime & 150 s & 96 s & 100 s \\
            \noalign{\smallskip}
            \hline
         \end{tabular}
   \end{table}