Source: Wikipedia (U.S. Census figures)
The City That Embraced Its Decline. (The Atlantic, 7/7/2016)
Youngstown, Ohio, created quite a stir a decade ago when it unveiled a novel plan for the city: It would stop trying to return to its glory days as a city of 170,000 people and instead embrace the idea that maybe smaller is better. The Youngstown 2010 plan reoriented the former steel-mill town toward providing services to the neighborhoods with the most people, converting abandoned land into green space, and supporting the burgeoning healthcare industry. In doing so, it hoped to keep the remaining 66,000 people from leaving. Since unveiling the plan in 2005, the city has lost only about 1,000 people.
I think it's more appropriate to conclude, the city has slowed its population loss.
Adding Mahoning County, of which Youngstown is the county seat, to the graph.
City of Youngstown
Mahoning Valley Historical Society
Youngstown Neighborhood Development Corporation