"...In a two-day audit of eight mail distribution centers, investigators discovered more than 572,000 delayed mail items on land. However, postal officials were only reporting 369,000 delays, essentially hiding 36 percent of the problem..."
Reference: billingsgazette.comWednesday, September 20, 2017
Postal Officials Under-Reporting Delayed Mail, Tester Calls for Firings
Tester wants firings after postal workers accused of delaying mail delivery