\begin{table}%t3
\caption{\label{table:3}Number of non-Io DAM emissions related to HCS, FS or RS.}              
%\centering
\par
\begin{tabular}{c c}     
\hline\hline \noalign{\smallskip}
IP structure &  N. emissions \\    
\hline                        
None  &  20 \\     
HCS  & 2 \\  
HCS+HCS  & 1 \\  
FS  &  1 \\  
FS+HCS  &  6\\  
FS+HCS+HCS  &  1 \\  
FS+FS+HCS+HCS &  1 \\  
FS+RS  &  1 \\  
FS+RS+RS  &  1 \\  
RS &  3\\  
\hline                                   
\end{tabular}
\vspace*{5mm}
\end{table}