The range varies a lot depending on the quality of the treatment. The early initial estimates were based on data from Wuhan, where hospitals were overwhelmed early. The later, lower numbers were from areas where all new cases had hospital beds and ICUs available if they needed them.

Problem is, given the current numbers, the projected total number of people who will require hospitalization, and of those that will require ICU, significantly exceed availability. So if it spreads too fast, and all these people get sick at the same time, we won't have enough beds to go around - and that will cause the mortality rate to spike again.