Cook County makes up most up most of Illinois population growth in 2012 Census.

[hopper]

Illinois grew by 44,600 people so far this decade while Cook County grew by around 36,700 people. That's a reversal from the 2010 Census when Kendall County grew by 110% by 60,300 people to 114,736 people and Cook lost around 182,000 people. So far Kendall has grown by 3,400 people in the 2012 Census up to 118,105 people.

Cook County:
2000 Census: 5,376,741
2010 Census: 5,194,675
2012 Census: 5,231,351

Population High

1970 Census: 5,492,369

Population Low:

1990 Census: 5,105,067

source: wikipedia

[hopper]

The 2012 census?

Well Census estimates.

[hopper]

I think that is a deceiving way of putting it. There are a lot of rural counties that are losing population, and Cook is counterbalancing that. There is also a lot of growth going on in suburban Chicago, mostly at higher rates, except for maybe Lake?

Yeah Lake has lost 300 people when comparing the 2010 Census to 2012 Census estimates.

[hopper]

Not really surprising, given that there's really no reason to live anywhere else in Illinois outside Chicagoland.

Well Kendall is outside Chicagoland.