Net approval at a point in time is the percentage of voters who approve minus the percentage of voters who disapprove, it’s not a delta from an earlier reading.

For net approval to be negative, more people must disapprove then approve.

+84 doesn’t mean an increase of 84 percentage points, it means 92% approval, 8% disapproval.

I don’t think this is initial approval minus approval 100 days in, I think it’s approval 100 days in minus disapproval 100 days in.

Is it possible that it’s % of variation compared to what it was on day 1? So if approval was 50% and on day 100 it’s 60% that’s +20 (20% of 50 = 10, 50 + 10 = 60)?