\begin{table}%t8
%\renewcommand{\arraystretch}{1.25}
\caption{\label{cfr_tab}Cluster formation rates (CFR) and~cluster lifetimes ($\tau$).}
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%\centerline
{
\begin{tabular}{rcccll}
\hline\hline
No & CFR                    &$\tau$     &$N_{\rm cl}$&Sample&Note\\
   &kpc$^{-2}$~Myr$^{-1}$    &Myr        &        &      &    \\
\hline
 1& 0.10~$\pm$~0.01           &256~$\pm$~12 &652     & tot  &  \\
 2& 0.31~$\pm$~0.03           &327~$\pm$~25 &259     & cmp  &  \\
 3& 0.23~$\pm$~0.03           &322~$\pm$~31 &195     & fld  &  \\
\hline
 4& 0.10                    & 231       & 70     & w71  & 1\\
 5& 0.18                    & 144       & 112    & p86  & 2 \\
 6& 0.25                    & 100       & 213    & j88  & 3\\
 7& 0.45                    & 14        & 100    & b91  & 4\\
\hline
\end{tabular}}
\smallskip
 Sample: No. 1...3 are the present study, No. 4...7 are
taken from the literature;
tot -- the total sample; cmp -- the sample of~clusters within the completeness area; 
fld -- the sample of field~clusters within the completeness area;
w71 -- Wielen~(\cite{w71}); p86 -- Pandey \& Mahra~(\cite{panma86}); j88 --
Janes et~al.~(\cite{janea88}); b91 -- Battinelli \&
Capuzzo-Dolcetta~(\cite{batin91}).
 \\
 Notes:  1 -- the Becker \& Fenkart~(\cite{baf71}) sample;
2 -- the Lund catalogue, 3rd edition; 3 -- the Lund catalogue, 5th edition;
4 --~clusters with $d\le 2$~kpc and $V_{\rm integr} \le -4.5$~mag.
\end{table}