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\begin{document}
\begin{tabular}{ll}
Source & Size [ $\text{\,Me\kern -0.1em V}$ \xspace] \\
\hline
Parton distribution functions& $9$ \\
Theory (excl. PDFs) total & $17$ \\
 \hspace{3mm} Transverse momentum model & $11$ \\
 \hspace{3mm} Angular coefficients & $10$ \\
 \hspace{3mm} QED FSR model & $7$ \\
 \hspace{3mm} Additional electroweak corrections & $5$ \\
Experimental total & $10$\\
 \hspace{3mm} Momentum scale and resolution modelling & $7$\\
 \hspace{3mm} Muon ID, trigger and tracking efficiency & $6$\\
 \hspace{3mm} Isolation efficiency & $4$\\
 \hspace{3mm} QCD background & $2$\\
Statistical & $23$\\
Total & $32$\\
\hline
\end{tabular}
\end{document}
