OK, someone is either making up nonsensical data or there's some obscure census data.  However much some of us really want Chicago to bloom, I have found nothing so far demonstrating that "It was estimated in 2006 that the population of Chicago was slightly over 3 million."  The latest census estimates put Chicago on a consistent decline, and even older Illinois estimates, which I had looked at before a long time ago and can't seem to find again (which aren't 2006) put Chicago projected, in 2006, at less than 3 million.  It doesn't even make sense on a theoretical level; it took 10 years (1990-200) to grow by like 112k people, I highly doubt that all of a sudden Chicago took that same level of growth in a little more than half that.  Someone find some solid data backing up that statement within the next few days or so, or I'll take it out.  (-  )