From the Document: "This Insight presents data on federal debt on or near Inauguration Days since 1961 taken from U.S. Treasury statements. 'Table 1' presents current-dollar debt levels. 'Table 2' presents inflation-adjusted debt levels. Finally, 'Table 3' presents debt as a proportion of the U.S. economy. Levels for August 2, 2021, the first business day after the most recent reset of the debt limit, and September 14, 2021, the date of the most recent Daily Treasury Statement [hyperlink], are also included."
CRS Insight, IN11754
Congressional Research Service: https://crsreports.congress.gov/