those numbers are for m2, or as many plants as you can fit into a meter 2 in a sea of green grow..
i never pay any attention to three things when looking at strains.. the first is the estimated yield.. like said above, there are way too many factors that can effect the yields of plants ime..
the second is flowering time as i find that most strains go for way longer then what the breeders say they do.. i've yet to really run an 8 week strain, and most of my indica stuff goes closer to 10 weeks..
and lastly is the thc levels..to me this one is obvious.. there is no proof backing up any of these numbers, so who's to say that they're not simply pulling them out of thin air, which in my opinion, a lot of them are..