I don't know where you found the tax thing, I couldn't find it. I only found the idea of refusing to offer sacrifices for the gods or the emperor.
About the number, I couldn't find final numbers, but I found this.
Nobody really knows exactly how many Christians died in the Diocletian
persecution from 303 to 311. Based on available evidence, Gibbon
estimated the total number of Christians martyred during that nine
years of persecution as no more than two thousand.
Only in that period.



The neighbors are starting to talk about all that smoke, you know.


