Basic Microeconomics (supply and demand), and Basic Macroeconomics (Taxes, GDP, spending...).
There are too few people who ever will take a basic economics class. You can tell by people freaking out when someone in government does something from the basic economic playbook.
I can't really guess well, because I'm not too sure. But from my experiences, roughly 1 in 20 have taken a basic economics class. Or at least from all the people I've met, 1 in 20 understand a basic economics class.