Whatever the number is, we know for a fact that it was

1. Extremely painful to Americans, and became one of the main pillars of their election.

2. Nowhere near high enough to cause any reduction in the USA's debt burden.

I think modern Americans are way too soft to even imagine the sort of inflation that'd be required to erase their debts. Things have been too good and too stable for too long to understand what country-wide economic hardship would be like, and even if they somehow decided to choose that path, they'd panic quit it long before it was done long enough to have any effect.