In 2006 – admittedly, not one of the best years for prudent  11  Homeowner DTI is measured at the time of the survey, not at the time of loan origination, and may understate the number of affected households if household finances improve after the purchase of a home.
A recent study by CoreLogic suggests that 25 percent of mortgages originated in 2010 had DTIs greater than 43 percent. See Sam Khater (2013), “The Mortgage Market Impact of Qualified Mortgage Regulation (PDF),” The MarketPulse, vol. 2 (February), pp. 3–6.