The number of positive CV tests, morbidity, mortality, and ultimately recovered patients is a differential equation. For example, the number of new cases is exploding at a much higher rate than the death rate because there is the inherent 30-40 day (or so) lag period between the two. It will take several months to determine what the real numbers are because it will take quite a while to approach a steady state. As an estimate one can look backwards at the number of positive tests say 30 to 40 days previously(assuming mass testing from a reputable source such as South Korea) and compare that number with the number recovered and number of deaths. I think that data from South Korea will be very informative about 24-30 days after they initiated their mass testing.
Of course there are a lot of variables involved such as some locations possibly having more virulent and/or severe strains, possible populations genetic differences, differences in healthcare systems, etc.