Is there a similar breakdown of companies YC lost money on?
Think of it this way with Heroku:
YC gets 6-7% initially and probably ends up with close to 3% after Series A and B. That's $6.2M on the $212M exit price.
A single exit like Heroku returns them enough to run YC for at least a couple years and returned >10x for other investors.
So while you could show that, it doesn't really matter to YC or to investors, because they have those 2-3 huge wins.