
\documentclass{article}
\begin{document}


\begin{table}
\begin{center}
\caption{KEKB and PEP-II}
\begin{tabular}{lll}
\hline\hline
&\multicolumn{1}{c}{KEKB}       &\multicolumn{1}{c}{PEP-II}\\\hline\hline
1993& &(10.22  SSC demised)
\\\hline
1994&4 Start construction       &1 Start PEP-II construction
\\\hline
1995&12 Start removing TRISTAN \\
 &\\\hline
1996 &ARES, SC cavity test at AR
 &\\\hline
1997&&6.16  HER beam first stored
\\\hline
1998&5  Linac upgraded & 7.16  LER beam first store\\
&12.13 HER beam first stored &7.23  First collisions
\\\hline
1999&1.14       LER beam first stored
        & 2.8 Lpeak = 5.2x10$^{32}$cm$^{-2}$s$^{-1}$\\
&5.1 BELLE rolled in
        & 5  BABAR rolled in \\\hline
2000&8 LER solenoid winding started
 &\\\hline
2001& 8.14  discovery of CPV
 &
2001.8.14  discovery of CPV
\\\hline
\end{tabular}
\end{center}
\end{table}

\end{document}

