Great work as usual. A couple of comments:
PCR can remain positive for a long time after infection and recovery. The practice of declaring a first positive test a “case”, while understandable, now is known to include infectious and non-infectious people, which, to the extent that it is driving public policy may be an error. It is not possible currently to test for infectious virus on a mass basis, it may be that + PCR + IgG antibody = noninfectious state, TBD.
The decline in deaths is misleading to a degree (except of course to the people who are not dead). This is a complicated, fascinating disease with a steep learning curve for how to take care of critical COVID illness. A person who would have certainly died on 3/20 and who would have probably died on 4/20 will most likely survive today.
The trigger for critical COVID illness remains unknown, although the risk factors (age, diabetes, hypertension, obesity) are the same all over the world. There are people with none of these risk factors who sicken and die, so it’s not something intrinsic to the risk factors per se, maybe genetics play a role.