Since Bill and Hillary Clinton left the White House in 2001, they have earned more than $230 million. But in federal filings the Clintons claim they are worth somewhere between $11 million and $53 million. After layering years of disclosures on top of annual tax returns, Forbes estimates their combined net worth at $45 million. Where did all of the money go? No one seems to know, and the Clintons aren’t offering any answers.

As Reported By Dan Alexander for Forbes:

From 2001 to 2014 the power couple spent $95 million on taxes. Hillary’s 2008 presidential run cost her $13 million. Their two homes cost a combined $5 million, and the Clintons have given away $22 million to charity. All of this is according to FEC filings, property records and years of tax returns. Add it up and you get $135 million. If the Clintons made $230 million, spent $135 million and have just $45 million left over, what happened to the other $50 million?

“That’s kind of strange,” says Joe Biden’s accountant, Walter Deyhle. “You have to report all of your assets. You have to report assets that are owned by your spouse.”

It seems unlikely that the Clintons could have spent all of it. Over 14 years $50 million averages out to $3.6 million in extra expenses per year, or $9,800 per day.

WHERE COULD THAT much money have disappeared? The Clintons have been speaking around the world for years, and they count millions in travel expenses under their businesses. It is unclear whether they have paid for additional travel expenses out of their own pockets. It seems unlikely, but they could have given it away overseas: Donations to foreign charities are not deductible and would not be listed on tax returns. Billionaires like Prince Alwaleed Bin Talal of Saudi Arabia,Lakshmi Mittal of India and Joseph Safra of Brazil have donated to their foundation. Maybe the Clintons are returning the favor?