The sources of the pension contributions could be a pension property tax levy, the maximum allowable Personal Property Replacement Tax or additional unrestricted revenues from the city budget.
A largely unasked question is becoming glaring: Is Illinois doing all it should to use artificial intelligence to make government cost less and work better? So far, the evidence says no.
That is a long way off, lots of things will change during that period.
Good luck getting illegals to fund pensions.