

\begin{longtable}{|l|r|r|r|}\hline
   Level of {\newline} Year &    N &    \multicolumn{2}{|c|}{Mortality}\\\hline
   \multicolumn{1}{|r|}{~} &    \multicolumn{1}{|r|}{~} &    Mean &    Std Dev\\\hline
\endhead
   1968 &    10 &    5.99000000 &    0.98933199\\\hline
   1969 &    10 &    5.77000000 &    1.39845152\\\hline
   1970 &    10 &    4.91000000 &    0.77952977\\\hline
   1971 &    10 &    4.80000000 &    1.30384048\\\hline
   1972 &    10 &    4.72000000 &    0.95078915\\\hline
\end{longtable}

