The U.S. Office of the Comptroller of the Currency reported on Wednesday that 5.3 percent of all residential mortgages that it tracks (about 64 percent of the outstanding total nationwide, or about $6 trillion in principal balances) were seriously delinquent, or more than 60 days behind, in 2Q09. That’s up from 4.8 percent during the first quarter of the year, and up from 3 percent a year ago.