\begin{table}%t6
      \caption{\label{tab:lit}Compilation of O\1~and P\2~measurements found in the literature.
      The distance we report is the target distance, it is also an upper limit for the cloud distances.}
                  %\centerline
{
         \begin{tabular}{lcccll}
            \hline\hline
             Sightline  &  $\log N$(O\1) & $\log N$(P\2) & $\log$~P\2/O\1 & reference  & comment\\
                       \hline
WD~0004+330 &$16.34\pm0.15$& $12.85\pm0.02$& $-3.50\pm0.15$&  {Lehner et~al. (2003)} & Star distance $D=97$~pc\\
WD~0131$-$163 &$15.85\pm0.11$& $12.78\pm0.09$& $-3.07\pm0.14$&        ''                 & $D=96$ pc\\
WD~1211+332 &$15.74\pm0.32$& $12.57\pm0.08$& $-3.17\pm0.32$&        ''                 & $D=115$ pc\\
WD~1528$-$163 &$15.80\pm0.08$& $12.40\pm0.30$& $-3.40\pm0.30$&        ''                 & $D=140$ pc\\
WD~1631+781 &$15.78\pm0.11$& $12.45\pm0.14$& $-3.33\pm0.17$&        ''                 & $D=67$ pc\\
WD~1634$-$573$^{{a}}$ &$15.50\pm0.04$& $12.08\pm0.07$& $-3.43\pm0.08$&        ''                 & $D=37$ pc\\
WD~1800+685 &$16.11\pm0.14$& $12.94\pm0.06$& $-3.17\pm0.15$&        ''                 & $D=159$ pc\\
WD~1844$-$223 &$15.97\pm0.19$& $12.59\pm0.10$& $-3.38\pm0.20$&        ''                 & $D=62$ pc\\
WD~2004$-$605 &$15.65\pm0.08$& $12.36\pm0.09$& $-3.29\pm0.11$&        ''                 & $D=58$ pc\\
WD~2011+395 &$16.04\pm0.07$& $12.59\pm0.14$& $-3.45\pm0.15$&        ''                 & $D=141$ pc\\
WD~2124$-$224 &$15.94\pm0.03$& $12.74\pm0.09$& $-3.20\pm0.10$&        ''                 & $D=224$ pc\\
WD~2211$-$495$^{{b}}$ &$15.34\pm0.04$& $12.04\pm0.10$& $-3.30\pm0.11$&        ''                 & $D=53$ pc\\
WD~2309+105 &$15.67\pm0.05$& $12.28\pm0.04$& $-3.39\pm0.07$&        ''                 & $D=79$ pc\\
WD~2331$-$475 &$15.48\pm0.05$& $12.18\pm0.10$& $-3.30\pm0.11$&        ''                 & $D=82$ pc\\
\hline
HD~185418 & $18.15\pm0.09$ & $14.72\pm0.10$ & $-3.43\pm0.14$ & {\rm Sonnentrucker et~al. (2003)} & $D=790$ pc \\
\hline
GD 246& $15.67\pm0.07$ & $12.29\pm0.10$ & $-3.38\pm0.13$ & {\rm Oliveira et~al. (2003)} &  $D=79$ pc \\
WD 2331$-$475 & $15.48\pm0.11$ & $12.18\pm0.20$ & $-3.30\pm0.25$ & ''&  $D=82$ pc \\
HZ 121 & $15.74\pm0.10$  & $12.57\pm0.13$ & $-3.17\pm0.17$ & ''& $D=115$ pc \\
\hline
$\zeta$Pup & $16.70\pm0.20$ & $13.38\pm0.05$ & $-3.32\pm0.21$ & {\rm Morton et~al. (1978)} & $D=450$ pc \\
\hline
$\zeta$Oph & $17.38\pm0.10$ & $13.98\pm0.10$ & $-3.40\pm0.14$ & {\rm Morton et~al. (1975)} & $D=200$ pc \\
\hline
$\alpha$Vir & $15.58\pm0.10$ & $12.40\pm0.15$ & $-3.18\pm0.20$ & {\rm York \&\ Kinahan (1979)} & $D=88$ pc \\
\hline
HD~47240 & $14.86\pm0.02$ & $12.60\pm0.10$ & $-2.26\pm0.10$ & {\rm Welsh et~al. (2001)} & $D=1800$ pc \\
\hline
Sk108 & $16.65\pm0.06$ & $13.39\pm0.04$ & $-3.26\pm0.07$ & {\rm Mallouris (2003)} & (SMC star) \\
             &               &                  &              &                           &  Metallicity $Z\sim Z_\odot$/4\\
\hline
Q0347$-$383$^{{c}}$ & $16.18\pm0.18$ & $12.48\pm0.09$ & $-3.70\pm0.21$ & {\rm Ledoux et~al. (2003)} & (DLA) \\
             &               &                  &              &                           &  Redshift $z_{\rm abs}=3.02485$, \\
                        &                 &               &               &                              &  $Z \sim Z_\odot$/10 \\
Q0347$-$383$^{{c}}$ & $16.12\pm0.12$ & $12.34\pm0.19$ & $-3.78\pm0.24$ & ''                        & (DLA) $z_{\rm abs}=3.02463$, \\
                          &               &                &                &                             & $Z\sim Z_\odot$/10 \\
\hline
LLIV Arch & $16.42\pm0.23$ & $13.21\pm0.12$ & $-3.21\pm0.28$ & {\rm Richter et~al. (2001)} & Z$\sim$Z$_\odot$  \\
\hline QSO HE 2243-6031  & $16.79\pm0.21$ & $13.42\pm0.10$ & $-3.37\pm0.25$ & {\rm Lopez et~al. (2002)} & (DLA) $z_{\rm abs}=2.33$,\\
             &               &                  &              &                           &   $Z\sim Z_\odot$/12 \\
            \hline
QSO 0000$-$2620  & $16.42\pm0.10$ & $12.63\pm0.04$ & $-3.79\pm0.11$ & {\rm Molaro et~al. (2001)} & (DLA) $z_{\rm abs}=3.3901$, \\
              &                &                 &                &                            & $Z\sim Z_\odot$/100 (Molaro et~al. \cite{Molaro2000}) \\
            \hline
         \end{tabular}}
\smallskip
 $^{{a}}$  Wood et~al. (\cite{Wood2002}) obtained a consistent ratio
$\log$~P\2/O\1~=~$-3.43\pm0.15$ for this sightline. \\
$^{{b}}$ H{\' e}brard et~al. (\cite{brard2002}) obtained a consistent ratio $\log$~P\2/O\1~=~$-3.29\pm0.23$ for this sightline.\\
 $^{{c}}$  Levshakov et~al. (\cite{Levshakov2002}) found $-3.63\pm0.03$ towards this QSO. We
choose to quote the measurement of Ledoux et~al. (\cite{Ledoux2003}) who obtained significantly better
VLT/\textit{UVES} data and had a particular attention on the saturation of O\1~lines.
   \end{table}