WebObservation: Q4 2023: 34,001,494 (+ more) Updated: Mar 4, 2024 3:00 PM CST. Units: Millions of Dollars, Not Seasonally Adjusted. Frequency: Quarterly, End of Period. 1Y | 5Y | 10Y | Max. to. Edit Graph. Share Links. Account Tools. NOTES. Source: U.S. Department of the Treasury. Fiscal Service. Release: Treasury Bulletin.