Isn't the anarcho capitalist theory that they can hire their own private security to protect their wealth? I imagine it would be like multiple Mafias running things.
It's generally held that government is a local monopoly on violence. Anarchy is in these terms an unstable local minimum, and the first two thugs who agree not to plunder each other's pockets have started the cycle of government again. Generally I think corporations and (other) criminal organizations rely fairly heavily on the existence of some state, even a nominal one. Criminal activity when you are the law is simply bad governance. Either way, you can't construct a society based on a logical contradiction.
This is why Republican/Libertarian efforts to eliminate or reduce Government is so fucking scary. Of course there are legitimate reasons to be concerned with limiting govt. overreach. But the Govt. is a required political social entity and we've gotta keep going. Whats baffling to me is that so many wealthy people don't get this. If the Government goes away, their wealth is gonna get torched/taken.
Anyways to answer your question: I don't know what the proportion would be, but likely indicators would be... unemployment level and uninsured rates. People with no healthcare and no jobs/money === desperate people whose survival instincts will kick in.