\begin{table}%t6 %\centering \par \caption{\label{abund_best}Circumstellar SiO fractional abundance, $f_{0}$, and the radius of the SiO line-emitting region, $r_{\rm{e}}$, with 1$\sigma$-errors, from the best-fit model. The reduced $\chi^{2}$ for the best-fit model and the number of observational constraints, $N$, are also given.} \small \begin{tabular}{lcccc} \noalign{\smallskip}\hline\hline\noalign{\smallskip} Source & $f_{0}$ & $r_{\rm e}$ & $\chi^{2}_{\rm red}$ & $N$ \\[1mm] \hline\noalign{\smallskip} {R And} & $5.1\pm4.9\times10^{-5}$ & $4.0\pm3.0\times10^{15}$ & 0.6 & 5 \\ {W Aql} & $3.0\pm1.0\times10^{-6}$ & $6.5\pm2.5\times10^{15}$ & 0.2 & 4 \\ {S Cas} & $9.0\pm6.0\times10^{-6}$ & $9.0\pm4.0\times10^{15}$ & 7.2 & 3 \\ {WY Cas} & $1.2\pm0.3\times10^{-6}$ & $1.3\pm0.7\times10^{16}$ & 2.2 & 3 \\ {V386 Cep} & $7.5\pm2.5\times10^{-5}$ & $3.0\pm2.0\times10^{15}$ & 0.7 & 3 \\ {R Cyg} & $3.0\pm1.0\times10^{-6}$ & $8.5\pm3.5\times10^{15}$ & 1.2 & 4 \\ {$\chi$ Cyg} & $1.3\pm0.7\times10^{-5}$ & $5.0\pm3.0\times10^{15}$ & 5.2 & 4 \\ {R Gem} & $1.3\pm1.1\times10^{-5}$ & $3.0\pm2.0\times10^{15}$ & 1.1 & 3 \\ {RX Lac} & $1.8\pm0.8\times10^{-6}$ & $3.6\pm2.4\times10^{15}$ & 1.0 & 3 \\ {Y Lyn} & $1.9\pm1.1\times10^{-6}$ & $3.5\pm1.5\times10^{15}$ & 0.9 & 3 \\ {EP Vul} & $2.3\pm1.7\times10^{-5}$ & $3.1\pm2.0\times10^{15}$ & 0.7 & 3 \\ {AFGL 2425} & $6.5\pm2.5\times10^{-6}$ & $4.3\pm3.5\times10^{16}$ & 1.2 & 3 \\ \noalign{\smallskip} \hline \end{tabular} \end{table}