Butler County grew by 400 residents last year thanks in part to significant population gains in the southern section.

Recent statistics released by the U.S. Census Bureau calculated population shifts between July 2011 and July 2012.

The numbers got a boost from Cranberry Township, which added 363 people, and Adams Township, which added 294 residents. Out of the 57 county municipalities counted by the census bureau, only 12 recorded a population increase. Some of those municipalities, such as Saxonburg and Seven Fields grew by only one person. Cherry Valley, Karns City and Valencia all reported no changes in population, while the remaining 42 municipalities all recorded varying levels of population decline.

Some like Petrolia, Portersville and West Sunbury only lost one resident, while some of the population declines were more pronounced. For instance, Butler lost 77 people while Butler Township lost 76 people.