FRED data: Federal Debt: Total Public Debt as Percent of Gross Domestic Product

https://fred.stlouisfed.org/series/GFDEGDQ188S

About what should should be the level of Federal Debt
https://fredblog.stlouisfed.org/2017/02/two-tales-of-federal-debt/?utm_source=series_page&utm_medium=related_content&utm_term=related_resources&utm_campaign=fredblog