I shouldn't have to Google it myself, you're making the claims. You can't just drop a whole bunch of numbers in a thread, present them as facts, and not cite any sources whatsoever. It does no one who is trying to learn about the subject matter any favors and isn't constructive at all.
I completely agree with this, however the tact could have been a bit better. I wouldn't mind having something like this officially added to the HN guidelines.
Use IIRC or AFAIK when you remember something, but don't remember exactly or cite a source for anything stated as fact.