
\documentclass[border=5pt,multi=true]{standalone}
\usepackage{standalone}
\usepackage{ifthen}
\usepackage{microtype}
\usepackage{lineno}
\usepackage{xspace}
\usepackage{caption}
\usepackage{graphicx}
\usepackage{color}
\usepackage{colortbl}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{upgreek}
\usepackage{hyperref}
\usepackage{hypcap}
\usepackage{cite}
\usepackage{mciteplus}
\usepackage{longtable}
\usepackage{multirow}
\usepackage{afterpage}

\begin{document}
\begin{tabular}{l|rrrrrrrr}
 & $F_{\rm L}$ & $P_1$ & $P_2$ & $P_3$ & $P'_4$ & $P'_5$ & $P'_6$ & $P'_8$ \\
\hline
$F_{\rm L}$ & $1.00 $ &         $-0.28 $ &      $0.14 $ &       $0.19 $ &       $-0.25 $ &      $-0.14 $ &      $0.01 $ &       $-0.13 $ \\ 
$P_1$ & &  $1.00 $ &        $-0.18 $ &      $-0.21 $ &      $0.08 $ &       $0.00 $ &       $-0.04 $ &      $0.06 $ \\  
$P_2$ & & &  $1.00 $ &        $0.13 $ &       $-0.14 $ &      $-0.11 $ &      $0.01 $ &       $-0.04 $ \\ 
$P_3$ & & & &    $1.00 $ &        $-0.11 $ &      $-0.11 $ &      $0.08 $ &       $0.07 $ \\  
$P'_4$ & & & & &    $1.00 $ &        $0.17 $ &       $0.06 $ &       $0.06 $ \\  
$P'_5$ & & & & & &     $1.00 $ &        $-0.04 $ &      $0.07 $ \\  
$P'_6$ & & & & & & &     $1.00 $ &        $0.07 $ \\  
$P'_8$ & & & & & & & &      $1.00 $ \\   
\end{tabular}
\end{document}
