The three big banks that reported full-year earnings recently all suggested that their experience with bad debts was less severe in the final quarter of their year (to September 2009) than was the case in earlier quarters. Aggregate industry data on impaired loans, however, tells a different story.New loan write-offs in the September 2009 quarter were $7.1 billion, according to Australian Prudential Regulation Authority data published by the Reserve Bank of Australia in its monthly Bulletin yesterday.This is down from $8.6 billion in the June 2009 quarter and still the third worst quarter since credit quality turned sour two years ago.The ratio of impaired assets to total assets, at 1.11 per cent, is only one basis point better than in the June 2009 quarter.APRA said write-offs in the September quarter were $4.1 billion, and the highest yet in the cycle.