"Mark Skidmore and Catherine Austin Fitts, former Assistant Secretary of Housing and Urban Development, conducted a search of government websites and found similar reports dating back to 1998. While the documents are incomplete, original government sources indicate $21 trillion in unsupported adjustments have been reported for the Department of Defense and the Department of Housing and Urban Development for the years 1998-2015."
https://www.forbes.com/sites/kotlikoff/2017/12/08/has-our-government-spent-21-trillion-of-our-money-without-telling-us/?sh=5af079687aef
https://www.forbes.com/sites/kotlikoff/2017/12/08/has-our-government-spent-21-trillion-of-our-money-without-telling-us/?sh=5af079687aef