It is unlikely that even reddit themselves are able to conclusively answer this, as the protests made many people leave and many other people come or come back.

The userbase "churned" a great deal, which serves to obscure the specifics.

To add to this, if I were spez, and I was bleeding users rapidly, I would be willing to employ bots to inflate my numbers. I sincerely doubt spez is more ethical than I am, and it takes no genius to come up with this idea.