In .nl and even .pl, once someone gets into "chemo" territory, they're no longer a full-time employee for at least part of the year. I have no idea how this is reflected in OECD data, but I would not be entirely unsurprised if this is a reprise of the "women in .nl don't work" trope, whereas in-actual-fact it's sort-of the opposite, except not full-time.