[Johnny555]

35 ft is a little pessimistic, the LD50 is 10.5m (~35 ft) for those with head and chest injuries, and 22.4m (~75 ft) for those without. Which is surprisingly far.

In patients with head and chest injuries, a 50% mortality rate was estimated to occur at falls from 10.5m, compared to 22.4m in those without injuries to head or chest

https://www.ncbi.nlm.nih.gov/pubmed/22860503

[avar]

Studies like this don't provide good data points for "if you jump[...]" as the GP mentioned. The data is gathered from people who either accidentally fell, or intentionally jumped not intending to live.

They can't just randomly recruit people and have them jump to their near-certain deaths from ever increasing heights due to pesky medical ethics boards.

This matters because a person who's forced to jump from a significant height out of desperation (e.g. to avoid a fire) is likely to take certain precautions that people who accidentally fall don't take, and those trying to kill themselves intentionally avoid.