For career U.S. Postal Service employees, the last few years have brought an unrelenting wave of cutbacks. In its latest annual report, the agency furnishes some eye-opening numbers on how the downsizing has affected different segments of its workforce. The overall career headcount declined by more than one-fifth from 2009 to 2013 (surely one of the sharpest drops in USPS history). But the ranks of clerks and nurses plummeted by one-third and the number of employees classified as “professional, administration and technical” fell almost as steeply. Virtually all of the cuts, it should be noted, were accomplished without reductions-in-force. The one sector to grow during that…