[Tex/LaTex] Inserting a small vertical space in a table

positioningspacingtables

Is there a way that I can insert a small space in a table?
When I use a superscript, the number touches the \hline.

\documentclass[9pt,letterpaper]{article}
\usepackage{helvet}
\renewcommand{\familydefault}{\sfdefault}

\begin{document}
\begin{picture}(0,0)

\put(20,-136){\mbox{    
        \footnotesize   
        \begin{tabular}{ p{8em}  r  r  l }  
        \hline      
                        & Total     & Average   & Unit   \\
        \hline      
        Area1           & 419773    &   9.15        &  \emph{m$^2$}      \\      
        Area2           & 0     &   0       &  \emph{m$^3$}      \\
        \hline  
        \end{tabular}
    }}  

\end{picture}

\end{document}

I tried inserting \vspace but this does not move everything, just one cell.

\vspace{0.001 in} Area1 & \vspace{0.001 in} 419773  &   \vspace{0.001 in} 9.15      & \vspace{0.001 in} \emph{m$^2$} \

My preference would be to adjust this without an external package, as I am using an old version of LaTeX on a server that I cannot replace.

Best Answer

use

\rule{0pt}{4ex}    

in the first column of that line.