Less than 1/3rd of the velocity will come from the last 1/3rd of the fall.

If you’re going X speed after 2 stories, you’d be going sqrt(3/2)X = 1.22X after the last 1/3rd, ignoring drag.

Energy increases linearly with fall height though, and energy is probably what mostly kills you. (Again ignoring drag.)

Ah, because after that first 2/3rds, you're going too fast to have time to accelerate much more.

The first quarter of the fall distance takes half of the time.

Wow, thanks! So totally reverse from what I was assuming.