So, a statistically insignificant number of times then?

It’s a data point, which Lord of the Flies isn’t. Yet the book has huge cultural sway. The point being made is that stories of violence and greed are often amplified whereas those of healthy, normal human interaction aren’t.

Anon is correct. In the only documented case of children actually becoming castaways, they proved the premise of Lord of the Flies false. They all survived for a year, treated wounds, planted a food garden and even kept a fire alight. Read more about it in Human Kind by Rutger Bregman.