Huguenot pastor life expectancy

While reading about the St. Bartholomew’s Day Massacre to my kids this morning during history, I came across this claim. “ 72 protestant churches were set up in and around Paris. An untold number met in hiding to worship in the wilderness. Most pastors of these flocks were graduates of Calvin’s Academy in Geneva. Due to the severity of the religious wars, their life expectancy was only about six weeks!” This is a shocking claim, and humbling if true, like most things I learn about my fathers in the faith. I can’t find any sourcing with a google search, so I wondered if anyone here might be able to help with the life expectancy claim in particular.