CEDAR RAPIDS — Higher education was among the big winners at Iowa’s casinos and racetracks that paid the state $313.9 million in gambling revenue in fiscal 2015, according to a report Tuesday from the Legislative Services Agency.The winnings were indirect, however, coming from the $144.3 million or 46 percent of the gambling revenues funneled into the Rebuild Iowa Infrastructure Fund, which includes funding for tuition replacement and building projects at Iowa’s three regents’ universities.Among the major line items in RIIF are $30.2 million for tuition replacement at the regents’ universities to pay the debt service on academic revenue bonds.