The serious delinquency rate for mortgages in the Federal Housing Administration portfolio declined about 7%  in the first quarter of 2011 from one year ago. The 8.29% rate dropped from 8.9% a year earlier, according to a quarterly update from the FHA. In the fourth quarter of 2010, the delinquency rate was 8.84%. All rates were reported on a seasonally adjusted basis. FHA attributes the decline to higher quality mortgages originated from 2009 to 2011. The agency said mortgages from those most recent vintages currently comprise about half of all FHA insured loans in terms of volume. "The 2009 book is now starting to enter its peak default period (years two through four), but it is expected to perform much better than did its predecessors," the FHA reported. "At this stage in its seasoning, the 2009 book has claim rates that are less than half those seen at the same stage for the 2005-2008 books." Loans originated in 2007 and 2008 now only make up about 15% of the FHA's active portfolio, compared to 19% one year ago. The delinquency rate for the 2007 vintage is 22.44%, while the rate in the 2008 vintage is 19.65%. Loans originated before that time period are defaulting at a rate of 11.59%. FHA endorsed more than 371,000 forward loans and more than 18,000 reverse mortgages in the first quarter of 2011, providing a total $72.1 billion in new insurance. That is up slightly from $71.4 billion the previous quarter. "FHA single-family insurance activity in the quarter was marked by a decline in home-purchase endorsements, which was mostly offset by an increase in refinance activity," the FHA said. Still, dollar volumes in this quarter were more than 16% below the year-earlier period level of $86.4 billion, the agency added. The FHA expects declines in insurance volumes in the next quarter as loan originations trended downward in the latest quarter. The collective dollar volume of loans originated for FHA insurance in the first quarter fell 33% compared with the year-earlier period. This is attributable to a 44% decrease in home-purchase originations and a 16% decrease in refinance originations, the FHA said. Write to Christine Ricciardi. Follow her on Twitter @HWnewbieCR.