320 YC Companies X $30k/Company = ~$10M Investment

Dropbox Return=~3% Share X $10BN Valuation=$300M

30X return for the entire fund even without accounting for companies such as AirBnB, Heroku etc.

I have heard of 30x/100x returns on specific investments e.g. Skype/Google/Facebook etc...

But for the entire fund itself- wouldn't that be a record?