New Census data show most of Illinois’ municipalities are shrinking. Six of the eight cities with more than 100,000 people lost population in the 12 months that ended last July. Communities that gained population were mostly in the Chicago suburbs. Peoria lost a bigger portion of its residents than any other city, seeing more than 1,400 people head for the door.

Demographer Joseph Bowman says the biggest contributor to the losses isn’t deaths or people leaving for other parts of the state.

He says it’s not retirees moving to sunnier climates either. Bowman attributes the majority of the loss to people moving to other states.

The largest group of people leaving the state are under the age of 18. Rockford moved down a spot in terms of comparative population. Illinois’ total population fell by 33,000 in the same year, dropping it to the 6th most populous state.