No I'm trying to look at larger data. Because if Islam itself was such an important factor, we would encounter Islamic extremism all throughout its history instead of just the last few hundred years. But we don't. Prior to the Reformation, Christianity had roughly the same amount of extremism as Islam. What then separated the two religions from that point forward, allowing Christianity to accept Enlightenment ideas but Islam to reject them? Lots of reasons, but poverty is a huge factor.
Let me try this again...
If the percentage of poor Muslims that become terrorists is significantly higher than the percentage of poor Christians (or Jews, athiests, Hindus, etc.)) that become terrorists, that doesn't necessarily prove that Islamism is the defining factor, but it does show that poverty is NOT the defining factor. It shows that, isolated to these two factors (poverty and religion), that the religion is more highly correlated to terrorism than is the level of poverty.
I suspect that, in addition, the percentage of wealthy Muslims that become terrorists is significantly higher than the percentage of wealthy Christians (or other). If true, this would further show that the religion is much more correlated than the level of poverty.