Re: “Has there been any flu that significantly exceeded 0.1% in the past 50 years?”
In the USA, the mortality rate for an “average” flu season is 0.2%.
The CDC uses statistical models to estimate the final mortality, so the margin of error is probably significant.
In the 1918-20 Spanish Flu epidemic - in the USA - the mortality rate was 2.5%.
The great killer was the “infection rate” - which was 30%.
I see a couple that reach 0.17%, but not 0.2%, and most are lower, as is the average obviously. Still, that is above 0.1. Most other models I have seen, put the US Flu/Pneumonia mortality at 0.1% and below.
The CDC also estimates over 15% are hospitalized. That number also seems high to me. But they obviously know more than I do...