Statistically, is it harder for an atheist to be a theist, or theist to be an atheist?

i always wondered this question. i hope that i dont get anyone's "religious/ non religious opinion", rather a statistical answer. i cant seem to find it anywhere. i wonder this because it seems logical that it would be harder for a theist to be atheist, since it would take alot of convincing and understanding to abandon the theory of eternal life after death. since lets face it, who really wouldnt want to life after death? especially if there are no worries. also most of the stories i here about atheist converting to theist, is that the atheist was born an atheist. possibly having no REAL understanding of theism. since they have no REAL experience. and plus the gift of eternal life would seem quite appealing. especially if you never had it before.