ZIP codes with at least one Panama Papers address have an average income of $104,000, and ZIP codes with at least 10 addresses make $111,000. That's nearly double the income of an average U.S. ZIP code at $66,000, according to data from the United States Census Bureau.

Using the SmartyStreets application program interface to run more than 3,000 U.S. addresses through the Postal Service database in order to validate the locations and fix ambiguous entries showed that the top 10 percent of ZIP codes held about half of all shell company addresses. Very few companies were linked to poorer ZIP codes.

Here's a breakdown of some of the areas that were most likely to show up in the database, with income levels in green and Panama Papers addresses in orange.