think about it this way, can you figure out "accurately" how much bitcoin i own? or can someone figure out how much bitcoin you own? and that's while we are both publishing a lot of information about ourselves on the internet (addresses in profile, posted elsewhere, linked addresses,...)!
so now the answer is simple, the information there is not accurate at all. it is all a guess specially when it comes to large amounts since those owning larger amounts are more careful about their privacy.