\begin{table}%t10
\caption{Mean [X/Mg] ratios for stars with [Mg/H]$<-2.9$, corresponding to the 
yields of the first supernovae. The r.m.s. is the scatter around the mean.}
\label{yieldsuper}
%\centering
\par
\begin{tabular}{lrrr}
\hline  \hline
          &      & rms &  $n$    \\     
$[$Na/Mg] & $-$0.84 & 0.22 & 11   \\
$[$Al/Mg] & $-$0.33 & 0.15 & 13   \\
$[$Si/Mg] & $+$0.21 & 0.14 & 14   \\
$[$K/Mg]  & $-$0.14 & 0.14 & 13   \\
$[$Ca/Mg] & $+$0.06 & 0.09 & 14   \\
$[$Sc/Mg] & $-$0.17 & 0.14 & 14   \\
$[$Ti/Mg] & $-$0.01 & 0.09 & 14   \\
$[$Cr/Mg] & $-$0.63 & 0.09 & 14   \\
$[$Mn/Mg] & $-$0.65 & 0.20 & 14   \\
$[$Fe/Mg] & $-$0.21 & 0.10 & 14   \\
$[$Co/Mg] & $+$0.13 & 0.17 & 14   \\
$[$Ni/Mg] & $-$0.23 & 0.13 & 14   \\
$[$Zn/Mg] & $+$0.15 & 0.19 & 14   \\
\hline
\end{tabular}
\end{table}