As of Tuesday, Minnesota had 60 confirmed cases of COVID-19, the disease caused by the novel coronavirus.

How does that compare to other states in the Upper Midwest? Because of how COVID-19 is being tracked, it isn’t an easy question to answer.

In terms of raw numbers, Minnesota and Wisconsin had the most confirmed cases in the Upper Midwest, higher than Iowa and the Dakotas.

Minnesota and Wisconsin are more populated than Iowa and South Dakota. So, the higher numbers of cases then don’t necessarily mean the disease is more prevalent there. Here is a look at COVID-19 cases per million residents.

South Dakota’s relatively small number of cases is more significant in its population of 884,000 than Minnesota’s larger cases out of 5.6 million people.

All of these figures exist in an unusual circumstance, however. Tests for COVID-19 remain in short supply in the United States, and many people who wanted to be tested have been unable to do so. These figures don’t reflect the number of people who may have COVID-19; they only reflect the current number of people who have tested positive. A state that tests fewer people for coronavirus will get fewer positive results, but that doesn’t mean it has fewer people with the disease.

As it turns out, Minnesota and especially South Dakota have tested far more people, adjusting for population, than Iowa and Wisconsin.

A final factor to consider is how many positive tests states are seeing compared to the number of tests they issue. If a state is rationing its limited supply of tests only to people with the highest probability of COVID-19 infection, they’ll get a higher share of positive results than a state that also tests lower-probability patients.

That’s exactly what the data shows, with Wisconsin and Iowa issuing few tests but finding many positives. Minnesota, which has issued more tests relative to its population, has been finding COVID-19 in less than 5 percent of its tests.

So few tests are available in the United States that all of these figures are likely underestimating the number of COVID-19 cases, in part because mild cases of COVID-19 can share many symptoms with more familiar diseases such as the seasonal flu.

MPR News will continue to provide updated information as fresh data becomes available.