Not sure if this helps, but often I’ve found LinkedIn reports the numbers of folks who have self-listed their workplace on LinkedIn as a particular company.
From what I’ve seen, this tends to be inaccurate for various reasons - people staying on their after they leave, people saying they work there when they don’t (sometimes there are company’s with similar or the same name elsewhere), maybe they actually work at a subsidiary/parent, m&a stuff, etc…. not always the case, but definitely found some issues with this.