Towards the bottom:

> Employee counts come from company reports via Yahoo Finance, with Wikipedia used where figures weren't available. They're not necessarily from the same date, and companies don't all count employees in exactly the same way.

> As the McDonald's and Welltower examples show, a company's reported workforce doesn't necessarily represent everyone whose labour contributes to its business.

Well, alright. I'm just not sure how useful this is. There's no way to normalize them but the data's presented as though they were. You also sum employees across sectors which compounds the errors.