I'm not sure about the percentage God would know but I would say that most abortions are committed by people that are not born again that don't know Jesus that are not saved, it certainly doesn't make it right but it's understandable because they live in darkness including moral darkness and not just spiritual darkness spiritually dead according to Ephesians chapter 2 and being blinded by the god of this world 2 Corinthians 4:4, the true answer to ending abortion is getting people born again or the New birth