如何在 longtable 中设置精确的间距？

Question

我想要制作下表，其中最左边一列的文本居中（红色虚线），如下所示：

我目前的工作如下：

\documentclass{article}
\usepackage{longtable,enumitem}

\begin{document}
    \centering
    \setlength{\arrayrulewidth}{0.2mm}
    \setlength{\tabcolsep}{14pt}
    \renewcommand{\arraystretch}{1.3}
    \begin{longtable}{|p{2.3cm}|p{4.9cm}|p{4.9cm}|}
        \hline
        &   \textbf{KROHN-RHODES DECOMPOSITION} &   \textbf{JORDAN-CHEVALLEY DECOMPOSITION}  \\
        \hline
        \endfirsthead
        \multicolumn{3}{c}%
        {\tablename\ \thetable\ -- \textit{Continued from previous page}} \\
        \hline
        &   \textbf{KROHN-RHODES DECOMPOSITION} &   \textbf{JORDAN-CHEVALLEY DECOMPOSITION} \\
        \hline
        \endhead
        \hline \multicolumn{3}{r}{\textit{Continued on next page}} \\
        \endfoot
        \hline
        \endlastfoot
        \textbf{Purpose} & To decompose the semigroup of EEG signals in terms of affine scaling EEG signal groups, aperiodic semigroups, and the group of diagonal EEG signals. 
        & 
        To express the elementary EEG signals (unipotent and diagonal matrix of EEG signals) as a sum of their semisimple and nilpotent parts. \\
        \hline
        \textbf{Main Results} & Theorem 1, Theorem \ref2, and Theorem 3.    
        & 
        Theorem 4 and Theorem 5. \\
        \hline
        \textbf{Interpretation} & \begin{itemize}[leftmargin=+.1in]
            \item The EEG signals can be described in terms of simple algebraic structures.
            \item The building blocks of EEG signals can be perceived as prime numbers.
        \end{itemize}   
        & 
        \begin{itemize}[leftmargin=+.1in]
            \item The elementary EEG signals can be written as a sum of their simpler parts, which is similar to prime numbers where some primes can be written as a sum of two primes.
            \item The results provide a substantial manifestation that the EEG signals contain some patterns similar to prime numbers.
        \end{itemize} 
        \label{}
    \end{longtable}
\end{document}

产生：

请帮忙。谢谢。