\begin{tabular}{@{}ccr@{}}
\toprule
                 &\multicolumn{2}{c}{\textbf{Starter}}\\
                          \cmidrule(rl){2-3}
\thead{°C / °F} & \thead{Recently fed?} & \thead{Amount (\%)} \\ \midrule
        30 / 86 & Yes & 5  \\ 
        25 / 77 & Yes & 10 \\ 
        20 / 68 & Yes & 15 \\ 
        30 / 86 & No  & 2.5\\ 
        25 / 77 & No  & 5  \\ 
        20 / 68 & No  & 10 \\ \bottomrule
\end{tabular}