\begin{table}%t2
%\centering
\par
\caption{\label{tbl:xcorr} Cross correlation between our results of
 the solar radii and solar activity indicators. From left to right:
 solar radius at 17 GHz, total solar irradiance, Wolf number and flux
 density daily means at 10.7 cm (S-component).}
\begin{tabular}{ccccc}
\hline\hline
  &  17 GHz &  Irr. &  Wolf N. &   10.7 cm\\[0.5ex]
\hline
{ He {\sc ii}}      &  +0.14   &  +0.20   &  +0.30   &  $-$0.12\\
{ Fe {\sc ix,x}}    &  $-$0.12   &  $-$0.38   &  $-$0.43   &  $-$0.40\\
\hline
\end{tabular}
\end{table}