\begin{table}%T2
\caption{\label{tab2}Cosine-approximation of the unweighted 90~GHz, 150~GHz and 
230~GHz observations (Fig.~\ref{fig3}), irrespective of surface region.}
\small%\centerline
{
\begin{tabular}{lccccc} 
\hline
\hline
Freq. & $\langle T_{\rm B}\rangle$ & $\Delta T_{\rm B}$ &~$\Omega$ & $N$ & rms \\
(GHz) & (K)                    & (K)                  & ($\degr$) &  & (K) \\ 
\hline
90$^{a}$  & 317 & 137 & 17.6 & 244 & 19 \\ 
150 & 295 & 176 & 17.5 & 40  & 34 \\
230 & 278 & 154 & 8.5  & 62  & 33 \\
\hline\end{tabular}}
\smallskip
$^a$ Only data of this paper.
\end{table}