\begin{table}%t3
\caption {\label{tab3}Synchrotron dissipation time (in unit of Gyr) in galaxy clusters
that allows to match observations (1~cluster in the ``empty'' region)
in a fraction of Montecarlo trials~=~10\% (Col.~5), 5\% (Col.~6), 1\% 
(Col.~7) and~0.3\% (Col.~8).
}
%\centerline
 {\begin{tabular}{cccccccc}
\hline\hline
${\cal N}$ & ${N}_{\rm corr}$ & ${N}_{\rm emp}$ & ${N}_{\rm ul}$ & 
$\tau_{10\%}$ & $\tau_{5\%}$ & $\tau_{1\%}$ & $\tau_{0.3 \%}$ \\
   &   &   &    &  (Gyr) & (Gyr) & (Gyr) & (Gyr) \\
\hline
17 & 5 & 1 & 11 & 0.35 & 0.42 & 0.57 & 0.68 \\
{\bf 19} & {\bf 7} & {\bf 1} & {\bf 11} & {\bf 0.32} & 
{\bf 0.34} & {\bf 0.51} & {\bf 0.60} \\
20 & 7 & 1 & 12 & 0.30 & 0.36 & 0.49 & 0.59 \\
17 & 5 & 1 & 11 & 0.69 & 0.84 & 1.14 & 1.35 \\
{\bf 19} & {\bf 7} & {\bf 1} & {\bf 11} & {\bf 0.64} & 
{\bf 0.68} & {\bf 1.01} & {\bf 1.20} \\
20 & 7 & 1 & 12 & 0.60 & 0.73 & 0.97 & 1.17 \\
\hline
\end{tabular}}
\par
\smallskip
Montecarlo simulations are carried out for three configurations: GMRT
clusters with $L_{0.1{-}2.4}>8.4 \times 10^{44}$~erg~s$^{-1}$ excluding
the two mini-halos (first line), GMRT clusters with
$L_{0.1{-}2.4}>8.4 \times 10^{44}$~erg~s$^{-1}$ (second line),
GMRT clusters with $L_{0.1{-}2.4}>8 \times 10^{44}$~erg~s$^{-1}$ excluding
the two mini-halos (tirdth line); total number of observed clusters
and their distribution are given in Col.~1--4.
We perform $10^5$ random extractions of ${\cal N}$ synthetic clusters
assuming a grid of extraction probability with~$f$ in the range 0--1 
(see text).
Upper part gives the case where clusters cross the ``empty'' region
two times, lower part gives the case where clusters cross
this region only one time.
\end{table}