Chances of receiving epic and unique?

I'm not sure if this helps with anything, but since it seems okay to do so(and the only thing I could think of that could help in someway) Is that I've cubed two separate items. Got a Scar Helmet from rare to epic in three cubes, and then to Unique in 11....used two more cubes to get the stats of my likings.

Then an Arnah Hat took 14 to epic and 5 to Unique....

Is this actually rather good and I might have gotten lucky, or is this just normal?