Despite the notoriety that subprime loans gained during the financial crisis, they are re-emerging as one answer to the tight lending standards that have shut out millions of would-be homeowners. Subprime loans, which accounted for about 15 percent of all new home loans in 2005 and 2006, are now just 0.5 percent of the mortgage market. Only a handful of lenders are offering them, at interest rates from 8 to 13 percent. But the market is picking up. The number of lenders responding to inquiries from subprime borrowers started to catch up to the number responding to prime borrowers beginning in the fourth quarter of last year. Large banks are looking at subprime borrowers because rising mortgage rates have killed off much of their refinancing business.