Statistically which round is least likely for someone to be ko'd in?

[Spray_resistant]

I was wondering yesterday just out of curiosity which round statistically are the least amount of fighters stopped in?

If I had to guess I would say its the 4th round.

I come to this conclusion because if someone is just overwhelmed and can't hang then his confidence is gone from the get go and he is out of there in 1-3, while if someone gets broken down over time its going to take until at least the 6th because these are fit conditioned athletes we are talking about here.

Any thoughts on this?

[Siggy]

i'd say round 12

[Spray_resistant]

Also, I just can't recall to many major fights ending in ko/tko 4.

The only recent one that I can think of of the top of my head was Bute/AndradeII

[Hi-Dro]

8th-12th
due to a fighter breaking the other one down throughout the fight