\begin{table}%t4
\caption{\label{tab:abundd}Relative abundances $n_{\xi} / n_{{\rm b}}$ of deuterium species at redshifts $z=1000$, $z=100$ and $z=10$ in the SBBC model.}
%%\centering

\par
\begin{tabular}{l l l l l}
\hline
\hline
& & & SBBC &\\
\hline
Species && $z=1000$ & $z=100$ & $z=10$\\
\hline
$[{\rm D}]$ && $2.1 \times 10^{-5}$ & $2.1 \times 10^{-5}$ & $2.1 \times 10^{-5}$\\
$[{\rm D}^+]$ && $2.0 \times 10^{-8}$ & $1.3 \times 10^{-9}$ & $2.0 \times 10^{-21}$\\
$[{\rm HD}]$ && $7.4 \times 10^{-18}$ & $7.7 \times 10^{-11}$ & $1.3 \times 10^{-10}$\\
$[{\rm HD}^+]$ && $1.8 \times 10^{-24}$ & $6.9 \times 10^{-19}$ & $4.6 \times 10^{-20}$\\
$[{\rm H_2D}^+]$ && $2.1 \times 10^{-27}$ & $3.8 \times 10^{-20}$ & $4.7 \times 10^{-20}$\\
\hline
\end{tabular}
\end{table}