Wisconsin and Nebraska were both removed from the quarantine list that takes effect on Friday, but two other states have been re-added to the list.

Those two states are Iowa and Nebraska.

If you're keeping track (and why would you be), as of last week, the list stood at 20 U.S. states and territories. Both Wisconsin and Nebraska were noted for dropping below the threshold required to remain on the list, but they needed a second week of numbers below the mark to be removed from the order.

It's like trying to keep up with baseball's divisional standings.

Iowa, Kansas and Utah all fell off the quarantine list last Tuesday after multiple weeks of case numbers below the city's threshold, but both Kansas and Iowa marked a return this week.

Here's how the restriction system for Chicago works. States are added to the list if they have "a case rate greater than 15 new COVID-19 cases per 100,000 resident population, per day, over a 7-day rolling average." If they fall below that threshold, they could be find themselves taken off the list.

The list of states currently on the restriction side of things includes Alabama, Arkansas, Arizona, California, Florida, Georgia, Idaho, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nevada, North Carolina, North Dakota, Oklahoma, South Carolina, Tennessee and Texas. Puerto Rico was also a recent addition.

Chicago's travel order is evaluated every Tuesday, with any changes taking effect the following Friday.

As has been pointed out before, these restrictions really do count on people to follow them. Chicago has no mechanism for checking to see if you're from a restricted state, or if you've quarantined yourself after arriving in Illinois. Plus, the restrictions do not effect those traveling for work, only leisure.

Those are the current rules for Chicago. Outside of Chicago's city limits is a different story. Governor Pritzker said the state likely won't require residents who travel to and from neighboring states to quarantine for two weeks solely because of that travel.