Every year around Christmastime, the Census Bureau releases its population estimates for each state for the 12 months ending on July 1. The numbers look dry on a sheet of paper (or on an Excel spreadsheet on your computer), but they tell some vivid stories. The more so when they reflect, as the numbers for 2008-09 do, the effects of a sharp downward shift in the nation’s economy. Given the recession, it’s not a surprise that percentage growth, at 0.86 percent, was the lowest in this decade, just a tad below the rate in 2002-03, and well below the peak...