I think the result of such an analysis depends heavily on your definition of "fake news".  Presenting falsehoods as if they are facts is the obvious definition, but there are many other shades of "fake news": Articles that ignore any inconvenient facts that may exist in order to promulgate a pre-existing agenda, Articles that present negative hypothetical outcomes based on events that haven't taken place yet, or Articles that imply something as a fact based on a few social media snippets that the author claims to be indicative of worldwide public opinion.  Frankly it takes a very objective and dedicated editorial director to avoid publishing fake news and unfortunately those people were among the very first to be laid off during the last three decades of the media's decline.