Census: Cook County was the only county among the nation's 10 most populous to shrink. Illinois is forfeiting more people than any other state, according to Census Bureau estimates.

Crain's Chicago Business reports:

After gaining residents each year since 2007, Cook County lost population during the 12 months ended last June. And Illinois is forfeiting more people than any other state, according to Census Bureau estimates.

Previously, metro Chicago countered population losses elsewhere in the state. That is no longer the case amid the state's economic and political challenges.

Census Bureau figures released today show the five collar counties gaining 5,180 residents, not enough to offset the 10,488 decline in Cook County during the period. The population of DuPage and Lake counties decreased slightly. That left Cook County with 5.2 million residents and the six-county region with 8.4 million.

Data for Chicago and other cities are scheduled to be released in late May, the Census Bureau said. A breakdown by race and other demographic factors will follow in June.

The 22,194 statewide drop in population—a 0.2 percent loss—was caused by more people moving out of state than moving in, a deficit of 67,535 that “natural growth” (births minus deaths) failed to offset. Illinois' net out-migration accounted for three-quarters of the total population decline of the 10-state Midwest region. Looked at another way, Illinois lost more people than all those other states combined.

As of mid-2015, Illinois had a population of 12.86 million, fifth in the country.

No word yet from Dick Durbin, Rahm Emanuel, or our Glorious Leader Barack Obama on why all of this is happening.