Santa's elves have been busy. Also on Christmas eve, and with minimal fanfare, the Senate approved increasing the national debt ceiling by $290B (or $2105 T*Bux) to $12.4T overall. While this isn't a huge percentage increase, it does suggest the prior limit of $12.1T will be reached shortly, if not already.
Another figure I recently saw was a expansion of public debt to $7.7T, nearly $2 trillion dollars higher than $5.9T owed at the end of 2008. "Public debt" is the portion of the national debt owed on treasury bonds. The rest, I understand, is debt owed to the American citizenry for Social Security and Medicare entitlements.
Federal tax revenues collected in 2008 was $2.3T
1. Congress Increases Debt Limit.