I dont know, most of the divorcees I know that are christian left because of abuse or the other person was unfaithful, or it might have been both. Some people marry but they dont marry another believer.
the bible actually says if you are already married dont leave, but you can let the other person leave if they dont want to be married to you anymore as we are not called to be in bondage.
The problem seems to be for women, an abusive husband actually wont leave. So they need to be the ones that leave with nothing but the clothes on their backs. For their own safety. Often the women take their children with them and have to sneak out otherwise the husband will come after them and threaten to kill them. Not kidding about that.