请问为什么做的表格不在例子环境中？

\usepackage{bm,amsfonts,amssymb,amsmath,float}\usepackage{sectsty}
\newtheorem{exm}{Example}

\begin{document}
\begin{exm} \label{ExmAppLin}

\begin{table}[H] \label{Table5OldSecurity}
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    \setlength{\belowcaptionskip}{10pt}
    \caption{The codes and sample means }%\[2mm]
    \centering
    \begin{tabular*}{9.3cm}{lccccc}
        \hline
        No.     & 1       & 2       & 3         & 4          &  5        \\
        \hline
        Code    &  600197    & 600287    & 600369    & 600547    & 600985 \\
        Mean(\%)&  1.7143   & 1.2049    & 1.2237    & 1.8759    & 0.3056 \\
        \hline
    \end{tabular*}
\end{table}    

\begin{table}[H]
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    \setlength{\belowcaptionskip}{10pt}
    \caption{Returns}\label{TableParameterSim1}
    \centering
    \begin{tabular*}{8.5cm}{lcc}
        \hline
        No.            &      Uncertain return      & Expected value (\%)  
        \\
        \hline
        $\tau_1 $ 603068 &      $\L(-20,20) $       &     0.00        \\
        $\tau_2 $ 603121 &      $\L(-30,25) $       &    -2.5          \\
        $\tau_3 $ 601828 &      $\L(-20,24) $       &     2.0          \\
        $\tau_4 $ 603056 &      $\L(-35,40) $       &     2.5          \\
        $\tau_5 $ 603192 &      $\L(-32,25) $       &    -3.5          \\
        \hline
    \end{tabular*}
\end{table}

\end{exm}

\end{document}
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