\begin{table}%t4
\par
\caption{\label{duza}Comparison of heliosheath supply of PUI with interstellar supply of PUI.}  
%\centering
\par
%\centerline
 {\begin{tabular}{c c c c}
\hline 
\hline
\noalign{\smallskip}
Species &  Heliosheath\tablefootmark{a}     &  I/S neutrals & Heliosheath/I/S    \\
 ENA PUIs&  ENA PUIs (g/s)  & PUIs (g/s)    &  source ratio\\
\hline
C       &                  $4.5 \times 10^6$             & $1.8 \times 10^5$ & 25 \\
N                 &        $4 \times 10^5 $    &  $6.3 \times 10^7$&$6 \times 10^{-3}$ \\
O           &              $3.7 \times 10^6 $        &  $6.7 \times 10^8$& $5 \times 10^{-3}$\\
Mg          &           $ 1.8 \times 10^5$&        $5.1 \times 10^3$&35\\
 Si          &             $3.2 \times 10^6$& $7.4 \times 10^1$&$4\times 10^4$\\
 S             &            $6.5 \times 10^4$&  $5.2 \times 10^2$&125\\
\hline
\end{tabular}}
\tablefoot {\tablefoottext{a}{Only the upwind section of the heliosheath is assumed to produce ENA.}}
\end{table}