\begin{table}%t3
\caption{Mean values for the intrinsic collision probability $\langle Pi_{\rm c} \rangle$ and the impact velocity~$\langle V \rangle$ for the different populations of our model.}
\label{Tabla3}
%\centering
\small
\begin{tabular}{lcc}
\hline\hline
{Populations}  & ${{\langle}} {Pi_{\rm c}} {{\rangle}}$   &  ${\langle} {V} {\rangle}$ \\
&  {\footnotesize {(10}${^{-18}}$  km${^{-2}}$~~yr${^{-1}}$)} & {\footnotesize {(km~s}${^{-1}}$)} \\
\hline
&  Main Belt-Main Belt   & \\
{\small IR-IR}    &  9.8   &  3.7  \\
{\small IR-MR}    &  8.6   &  4.4  \\
{\small IR-OR}    &  1.4   &  4.4  \\
{\small MR-MR}    &  1.7   &  4.3  \\
{\small MR-OR}    &  3.5   &  4    \\
{\small OR-OR}    &  2.74  &  3.3  \\ 
\hline
& Main Belt-NEA    & \\
{\small IR-NEA}   &  6.2   &  9.9  \\
{\small MR-NEA}   &  2.7   &  9.3  \\
{\small OR-NEA}   &  1.5   &  8.1  \\ 
\hline
& NEA-NEA  & \\
{\small NEA-NEA}  &  7.2  &  14.5 \\          
\hline
\end{tabular}
\end{table}