Illinois Suffered Steepest Population Decline in the Nation

The state's population shrunk by 37,508 people from July 2015 through last July, according to the report.

IL lost more people than any other state, with a drop of 37,508.

The Census estimated Idaho's population at 1.68 million in July.

Census officials said states in the South and West led in population growth. Eight states lost population over the one-year time period. A years-long oil boom that had brought new move-ins to the state ended abruptly the last year-plus as declining oil prices killed numerous new jobs. IL is the only Midwestern state that experienced population loss in 2016, for the third year in a row. The next two on the list were Florida and NY who had over 19.5 million people in their respective states and no other states came close to those four. At 0.3 percent that's well below the national average.

However, Texas had the greatest population growth in terms of raw numbers, with 432,957 new residents.

The West was the nation's fastest-growing region, followed by the South.

County-level population estimates won't be released until March, and city and town estimates will be released in May.

Utah took the title as the nation's fastest-growing state, with 2.03 percent growth.

"The state continues to experience annual population growth that serves as further evidence of relative economic strength of the state", she said, noting that an uptick in in-migration was the most noticeable difference in the 2016 numbers.

The population drop has been pronounced upstate: 41 of 50 upstate NY counties lost population between 2010 and 2015.