\begin{figure*}
\centering
{\scriptsize  
\begin{tabular}{l|rrl|lrrrrr}  
 \textbf{} & 
\textbf{} & 
\textbf{} & 
\textbf{}&\multicolumn{6}{c}{
\textbf{Historical Effort Data}}\\\cline{5-10} 
\textbf{Dataset} & 
\textbf{Features} & 
\textbf{$T=|Projects|$} & 
\textbf{Content}&
\textbf{Units}& 
\textbf{Min} & 
\textbf{Median} &
\textbf{Mean} & 
\textbf{Max} &
\textbf{Skewness}\\ \hline
  Cocomo81 &17&63& NASA projects& months&6&98&683&11400& 4.4\\
  \hspace{6 mm}Cocomo81e &17&28& Cocomo81 embedded projects&months&9&354&1153&11400& 3.4\\ 
  \hspace{6 mm}Cocomo81o &17&24& Cocomo81 organic projects&months&6&46&60&240& 1.7\\ 
  Nasa93 &17&93& NASA projects&months&8&252&624&8211& 4.2\\ 
  \hspace{6 mm}Nasa93c2 &17&37& Nasa93 projects from center 2&months&8&82&223&1350& 2.4\\ 
  \hspace{6 mm}Nasa93c5 &17&40& Nasa93 projects from center 5&months&72&571&1011&8211& 3.4\\ 
  Desharnais &12&81& Canadian software projects&hours&546&3647&5046&23940& 2.0\\ 
  SDR &22&24& Turkish software projects& months&2&12&32&342& 3.9\\ 
  Albrecht &7&24& Projects from IBM&months&1&12&22&105& 2.2\\ 
  ISBSG-Banking &14&29& Banking projects of ISBSG&hours&662&2355&5357&36046& 2.6\\\cline{3-3}
          \multicolumn{2}{c}{~}  & Total: 448& \multicolumn{7}{c}{~} 
\end{tabular}}
\caption{The 448 projects used in this study come from 10 data sets.
Indentation in column one denotes a dataset that is a subset of another dataset.
 For notes
on this data, see the appendix.}\label{fig:data}
\end{figure*}