Federal Reserve Notes, also known as United States banknotes are issued by the FED. They are in fact liabilities of the FED. The holders of the Federal Reserve Notes in principal should be able to redeem assets from the FED, so long as the FED in solvent. The assets used to be gold, now it seems just largely US government debt and the promise that government will pay it back and/or continue to serve its people.
Just how faster has the FED been printing the Federal Reserve Notes? Here are the chart and table:
|Date of Record||Federal Reserve notes, net of F.R. Bank Holdings (Billions)||Yearly Increase Rate||Yearly Increase Rate(5 Year Average)|
Federal Reserve H.4.1 Releases  Current FED H.4.1 Release: https://www.federalreserve.gov/releases/h41/current/ . Column: “Federal Reserve notes, net”.
|↑1||Current FED H.4.1 Release: https://www.federalreserve.gov/releases/h41/current/|