There have been claims made that Grindelwald is almost unfathomably much more evil than Voldemort, comparing the former to Hitler (though there is more to that comparison than just "evil", it also hearkens back to Grindelwald's connection to World War II).
Which of the two is responsible for the most deaths?
In the same way that dictators are held responsible for the deaths they caused and killings they ordered (without necessarily having personally murdered all those people), I want to know which of the two dark wizards, Grindelwald or Voldemort, is responsible for the most deaths.
If you can break your answer down into (estimated) total deaths, and personal killings, even better.
Related: Who was more skilled at magic: Grindelwald or Voldemort? [closed]