Last year, the U.S. Department of Labor collected more than $212 million in back wages owed to 163,000 people, but the agency is still looking for many of those cheated by their employers. Now, a recently improved searchable database could help reunite workers with that unpaid overtime. The Labor Department’s Wage and Hour Division sends out checks to the last known address of employees owed back wages, but many bounce back because of a move or other circumstances, according to agency officials.