\begin{center}
\begin{tabular}{ccccccc}\toprule
Protected & Fault
 & \multicolumn{2}{c}{Rob 4} & \multicolumn{2}{c}{Rob 3}&Rob 1\\ 
registers& type & 
 $\nu_{ev} $&$\nu_{pot}$ 
&$\nu_{ev}$&$\nu_{pot}$ 
&$\nu_{ev}$ = $\nu_{pot}$ \\\midrule
\multirow{2}{*}{character} &
SEU&     25.34\% & 100\% &  22.78\% & 100 \% &  2.72\%  \\ 
& MEU &  7.07\%  & 100\%  &  0.59\% & 100\% &  0\%      \\\midrule 

\multirow{2}{*}{state} &
SEU&  58.32\% &   100\%   & 55.30\% & 100\% & 44.61\%  \\ 
& MEU & 24.78\% & 100\%   & 2.22\% & 100\% & 0.10\%   \\ \midrule 

\multirow{2}{*}{shiftreg} &
SEU&     62.80\% & 100\%  &  58.90\% & 100\%  &47.30\%  \\ 
& MEU &  10.92\%& 100\% &  13.86\%  & 100\%  &0.62\%  \\ \midrule 

character/&
SEU&           25.87\% & 100\% &   19.54\% & 100\% &  0.30\%  \\ 
state& MEU &  24.78\% & 100\% &   2.12\% & 100\% &  0\%  \\ \midrule 

character/ &
SEU&             24.62\% & 100\% &  26.02\% & 100\% &  5.14\%  \\ 
shiftreg& MEU &  7.47\% & 100\% &  13.79\% & 100\% &  0.623\%   \\ \midrule 

state/ &
SEU&             100\% & 100\% & 100\% & 100\% &  100\%  \\ 
shiftreg& MEU &  100\% & 100\% & 100\% & 100\% &  100\%  \\
\bottomrule
\end{tabular}
\end{center}