TV6 Investigates examined thousands of new data points from the U.S. Census, and it reveals surprises: Despite assumptions people are fleeing Rock Island County for Scott, for example, Rock Island County netted 433 residents from Scott County over the last census. However, Bettendorf is on track to soon surpass Moline as the second-largest Quad City. Bettendorf added 8,000 residents during the last census period – more than all the other Quad-Cities combined.