Citigroup Inc. is required to pay $968 million to compensate the taxpayer-backed mortgage buyer, Fannie Mae, for over a decade of claims linked to faulty home loans.  In a recent statement Citigroup said that the agreement includes 3.7 million mortgages originated from 2000 to 2012 that were sold to Fannie Mae.  Even though payments are covered by existing reserves, Citigroup …