  This proceeding presents a new set of proton parton distribution functions,
ATLASepWZVjet20, produced in an analysis at next-to-next-to-leading-order in
QCD. The new datasets considered are the ATLAS measurements of $W^{\pm}$ and
$Z$ boson production in association with jets in $pp$ collisions at $\sqrt{s}$
= 8 TeV at the LHC with integrated luminosities of 20.2 fb$^{-1}$ and 19.9
fb$^{-1}$ respectively. The analysis also considers the ATLAS measurements of
differential $W^{\pm}$ and $Z$ boson production at $\sqrt{s}$ = 7 TeV with an
integrated luminosity of 4.6 fb$^{-1}$ and deep-inelastic scattering data from
$e^{\pm}p$ collisions at the HERA accelerator. An improved determination of the
sea-quark densities at high Bjorken $x$ is shown, while confirming a
strange-quark density of similar size as the up-and down-sea quark densities in
the range $x\sim$ 0.02 found by previous ATLAS analyses.
