\begin{tabular}{|l|r||r|r|r|r|r|}
\hline
Serial & Diameter & \multicolumn{5}{c|}{Percentiles of age} \\
Correlation & (cm) & 5th & 25th & 50th & 75th & 95th \\
\hline
0.0 & 6.0 & 10.7 & 15.4 & 19.5 & 23.5 & 30.2 \\
0.4 & 6.0 & 9.4 & 15.4 & 20.8 & 26.2 & 36.9 \\
\hline
\end{tabular}