I think the ~17% in "costs covered" by their taxes is a bit generous.
Most, if not all, are uneducated and cannot get regular jobs working for companies, so they go on the dole and work side hustle type jobs in yard work, house cleaning, selling wares on street corners, etc.
All of that $$ is unreported.
Meantime, they overwhelm schools, clinics, hospitals, etc. causing the taxpayers to pick up the tab.