4/25    Is there a govt agency that keeps track of how many people are moving
        in and out of a region?  I'm interesting the population growth
        patterns in the Bay Area.  Down to the county level.  And no, census
        data is no good because it happens once every 10 years.  I need
        year-to-year data.  Thanks.
        \_ Try DMV.  I think that's the agency which the most people are
           required to register (most adults have driver's license, some of
           the adults who don't driver get IDs), so that's most likely the
           agency with the most accurate data that exist.  Hmm, actually IRS
           may be better.  Most adults file with IRS, and most children are
           dependents of some adults.
        \_ The full census may be only every ten years, but the Census Bureau
                is constantly collecting and tracking data like this.
        \_ IRS.  They know more about you than the census bureau.  Also county
           tax recorder but not as accurate.