\begin{table}%t5
%\centering
\par
\caption{Electron temperature fluctuations.}
\label{fluctuations}
\begin{tabular}{llll}
\noalign{\smallskip}
\hline
\hline
\noalign{\smallskip}
 Object   & $t^{2}_{\rm s}(\rm Bal)$  &  $t^{2}_{\rm s}(\mbox{\ion{N}{ii}}) $  &$t^{2}_{\rm s}(\mbox{\ion{O}{iii}})$ \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
NGC 1535 &   0.0003   &        &   0.0027 \\          
NGC 2438 &            & 0.0003 &   0.0032 \\
NGC 2440 &   0.0078   & 0.0041 &   0.0011 \\
NGC 3132 &            & 0.0006 &   0.0047 \\
NGC 3242 &   0.0034   &        &   0.0015 \\
NGC 6302 &            & 0.0097 &   0.0050  \\
NGC 6563 &            & 0.0005 &          \\
NGC 6781 &            & 0.0021 &          \\
NGC 6853 &            & 0.0016 &          \\
NGC 7009 &   0.0008   & 0.0011 &   0.0023 \\
\hline
\end{tabular}
\end{table}