NORMALLY I would get whiny about "do you own googling", but I have known tony for an ungodly long time. lol

for the best aggregate corona numbers, I get them here. MOSTLY because I can cut and paste the grid into a spreadsheet.
(THey have citations, going to first sources, lol I was looking at a korean newspaper link in hangul.)

https://www.worldometers.info/coronavirus/

For the flu, my go to source is the CDC
https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm
They are estimates for this season in the US, you can find all the other seasons there too.
10 to 20% infection rate.
~0.1% CFR

And I found THIS article, on HOW to Calculate CFR during an outbreak to be ... informative.
https://www.worldometers.info/coronavirus/coronavirus-death-rate/#correct

Sure, we wont know the "exact number" for ...well, we never will.
We will always have to estimate. But the accuracy will improve.
At some point we will have massive amounts of random, community testing, to determine the true infection rate. Unless 60% gets it, and then well, we dont need a better answer than CRAP THAT WAS A LOT.

The CFR gets harder, if you have the flu, and get this, did the flu kill you, CV19, both? How does it get reported?

And .... if we get the NIGHTMARE 1 to 6 million dead, will we actually be able to determine what they all actually died from?

here's to hoping that we slowed this enough ...