The US Federal Reserve paid about 77.7 billion U.S. dollars to the government, down from its payment made in 2012, the central bank announced on Friday. The preliminary unaudited figure was 12 percent less than the amount of 88.4 billion dollars in 2012, the highest in history, the Fed said in a statement. Last year, the Fed made an estimated net income of 79.5 billion dollars from the Treasury bonds and mortgage-backed securities it purchased to boost the economy. Since the onset of the financial crisis, the Fed has conducted three rounds of quantitative easing programs to push down borrowing costs and boost economic growth. Those efforts have attracted sharp criticism both at home and abroad, but generated large profits for the U.S. government as the central bank earns interest on the assets. The Fed's portfolio of securities and other assets has swelled to more than 4 trillion dollars from about 80 million dollars in 2007. It paid a total of more than 360 billion dollars to the Treasury Department from 2009 through 2013. The central bank is funded from interest earned on its portfolio of securities. After covering the expenses, it makes a payment of the remaining income to U.S. Treasury Department.