The census numbers for Waverly are in. Waverly’s official population is 10,394. That is up from 9,874 in 2010. In fact, Waverly’s population has increased every decade since the first set of data in 1870. There were 2,291 people counted in that first census in 1870. Bremer County’s population went up by about 700 people from 2010’s total. There are 24,988 in the county now, compared to 24,276 in 2010. Butler County’s population is down by around 500 people. 14, 334 people now live in that county. The state of Iowa’s population went up slightly in the last decade. There are currently 3,190,369 Iowa residents. In 2010 there were 3,046,355 residents.