Congressional net return from the Federal Reserve

We have two graphs, one is federal reserves net distribution to treasury and the other is Treasury debt held. We can compute the Fed's return on treasury assets.
2008 32/800 = .04
2009 47/500 = .094
2010 80/800= .1
2011 75/1600 = .05
2012 88/1600 = .055
2013 78/2100 = .037

The economy earns about 3.6% in nominal terms, more than the Fed. The Fed is now useless to Congress, the take off point has arrived, Congress is on its own.