Last year was the best economy the Tri-Cities has seen in five years. It was the first year since 2012 when the seven-county area posted real economic growth from the previous year. With that said, 2017’s real total economic output – gross domestic product (GDP) – has declined 5.7 percent ($979 million) from its 2011 peak, according to recently released data from the Bureau of Economic Analysis (BEA).