My best guess would be that the French study based it's results on the entire population, whereas the UK stats are drawn only from laoratory confirmed cases; th

My best guess would be that the French study based it's results on the entire population, whereas the UK stats are drawn only from laoratory confirmed cases; thereby ignoring the large number of completely symptom free people, as well as comorbidities. The stats for young people without pre-existing health conditions are wildly lower than the already very low mortality rates.