On numbers from https://news.ycombinator.com/item?id=22432358 (and those numbers are not necessarily accurate for lots of reasons) the death rate is below 0.4% for all age groups below 49. Then it increases exponentially. I'm curious what the comparative age breakdown of the 1918 flu was, particularly given that a lot of people would have been malnourished due to the war, and health care was not as advanced as now.