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\begin{document}                                                        
\begin{tabular}{|l|c|c|c|c|} \hline
 Tier    & Targetdosis &  Deff(alt)   &  Deff(neu)  &  $\Delta_{rel}$ \\ 
         &    [Gy]     &    [Gye]     &    [Gye]    & (alt-neu)/alt   \\ \hline
\hline
 Arno    &     2.8     &     5.6      &     4.8     &    -14\% \\ \hline
 Bruno   &     1.6     &     4.0      &     3.2     &    -20\% \\ \hline
 Caesar  &     2.7     &     5.4      &     4.6     &    -15\% \\ \hline
 Dora    &     1.7     &     4.2      &     3.4     &    -19\% \\ \hline
 Erich   &     4.0     &     6.9      &     5.9     &    -14\% \\ \hline
 Fritz   &     3.9     &     6.9      &     5.7     &    -17\% \\ \hline 
\hline
 Gerda   &     7.5     &    10.2      &     8.9     &    -13\% \\ \hline
 Hans    &     7.5     &    10.2      &     8.9     &    -13\% \\ \hline
 Inga    &     5.2     &     8.1      &     6.9     &    -15\% \\ \hline
 John    &     7.5     &    10.2      &     8.9     &    -13\% \\ \hline
 Karl    &     7.5     &    10.2      &     8.9     &    -13\% \\ \hline
 Linus   &     5.2     &     8.1      &     6.9     &    -15\% \\ \hline
\end{tabular}
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