Maricopa County, Arizona is the largest growing county over the tested period, surpassing Harris County, Texas. The latter had been fastest growing over the last eight consecutive years. Texas, which gained four seats in the last reapportionment, looks to be gaining several more in the next shuffling of the 435 congressional seats that will occur post 2020. Four of the top ten largest growing counties are from Texas.
In addition to Texas and Arizona placing counties on top ten largest growing counties list, Florida (2 counties – Orange and Hillsborough), Nevada (Clark County), Washington (King County), and California (Riverside County) also recorded entries.
The fastest growing list is also interesting. San Juan County, Utah, with an annual growth rate of 7.56%, is the nation’s fastest growing county. Two other Utah counties, Wasatch and Juab, also made the list. Together, Utah and Texas contain 60% of the top ten fastest growing counties. Dallas County, Iowa, Florida’s Sumter County, Crook County, Oregon, and Kittitas County, Washington round out the top ten.
The top growing metropolitan areas are a bit different. Here, The Villages in Florida again leads the fastest growing metro list. The Myrtle Beach, South Carolina, and Bend, Oregon areas are second and third. Colorado, Florida, Utah, and Texas also had entries on this list.
Chicago’s Cook County led the nation in lost population, mostly because more than 66,000 residents moved away during the tested one-year period. Wayne County, Michigan (Detroit), and Baltimore County, Maryland, were second and third in lost population. Some of the other top ten metro areas losing population are Cleveland, Long Island, NY, Milwaukee, Pittsburgh, and St. Louis.
The apportionment formula is a complicated mathematical equation that yields the large states gaining and losing seats more quickly than the smaller ones. Therefore, the growth patterns must be unusually significant for a small state to gain or lose a seat. The fact that Nevada, for example, has gained three seats when they were only an at-large state in the 1970 reapportionment shows just how stunningly large their growth pattern has been over the last 40 years.