What about the number of atheists killed for their beliefs vs. the number of religious martyrs?

What about the number of atheists killed for their beliefs vs. the number of religious martyrs?
In terms of sheer numbers, which religion is responsible for the most deaths? How does that compare to the number of deaths for the sake of atheism? What about the number of atheists killed for their beliefs vs. the number of religious martyrs?

What about the number of atheists killed for their beliefs vs. the number of religious martyrs?