CBO has compiled historical statistics on federal debt held by the public reaching back to 1790, measured against the size of the economy that existed at the time. The resulting line graph first appeared in the agencys December 2005 Long-Term Budget Outlook. The data on federal debt come from the Department of the Treasury and the Board of Governors of the Federal Reserve System, and the data on the gross domestic product come from a variety of sources, both private and governmental, as enumerated in the spreadsheet that CBO is providing. Most recently, in the July 2010 issue brief Federal Debt and the Risk of a Fiscal Crisis, the historical data were paired with projections showing two scenarios for the long term, through 2035.