Debit-card interchange fees for the largest U.S. banks fell 45 percent in last year’s fourth quarter from 2009 as new caps under the “Durbin amendment” took effect, according to data compiled by the Federal Reserve, Bloomberg reported. Average interchange fees for so-called non-exempt issuers, or banks with more than $10 billion in assets, dropped to 24 cents on average during the quarter, compared with 43 cents two years earlier. The shift occurred as limits championed by U.S. Sen. Richard Durbin, an Illinois Democrat, took effect. Average fees received by banks and credit unions with less than $10 billion in assets remained at 43 cents during the fourth quarter, the data show.