Left: Self-normalised yields of e$^{\pm}$ $\leftarrow$ W$^{\pm}$ and associated hadrons as a function of the normalised charged-particle pseudorapidity density. The linear behaviour $y=x$ is also shown as a dash-dotted line. The statistical and systematic uncertainties of the measurement are shown as vertical lines and open boxes, respectively. Right: Double ratio of the self-normalized yields of $e^{\pm} \leftarrow \textrm{W}^{\pm}$ to the self-normalised charged-particle multiplicity in pp collisions at $\sqrt{s}=$ 13 TeV.