Where's you come up with those wildly different numbers?

“Where did you come up with those”
The CDC last reported he total disease burden of COVID as of the end of 2020 (to my knowledge). They estimated that 83 million Americans had COVID last year ( most undiagnosed by testing, many asymptomatic).
But the peak was this year (January),so I roughly estimate that we should have gotten to 110 million (1/3) by now, at those rates.
Dr. Makary of John Hopkins published an Op-Ed in the Wall Street Journal, where he projected herd immunity effects beginning in April (2021). He used different estimation techniques for the number of infections that had already occurred, such as extrapolating from known case fatality rates, across the number of deaths within the total population. He estimated more like half had already been exposed (150-180 million). I believe that was in February, maybe March, when he published his estimate.
John Hopkins is one of the authoritative sources for data, reported on the CDC website.
Those two estimates were the basis for me estimating that 1/3 tp 1/2 of the American population has already had COVID.