When Joe Brannen began his service as a Statesboro city councilman in 1998, the city had a population of about 20,000 and an annual operating budget of about $17.5 million. As Brannen prepares to leave public office 15 years later — the last four of which he has served as mayor — the city’s population has grown to 31,500, and the budget has ballooned to nearly $50 million. “We have grown into a big city.