Hey, that's me!
andosalado, it's possible that the chart you saw contained some data of how much money the hands had won for some player over a large sample.
This value is a bit dubious because it doesn't take into account the present conditions (position, opponents, image, stack sizes) but it can serve as a general idea of what a hand is "worth."
There's no real other way to determine EV of individual hands before the flop. In the future, with much more powerful computers and very advanced programs, it ought to be possible to set up simulations to calculate it, but today the value can mostly be divided into "positive," "probably positive," "neutral," "probably negative" and "negative" and the divisions will be a little bit off depending on the specific circumstances.