[jacalata]

The article explains that they rank the level of "self-made-ness" out of 10, with 10 being from a poor family with no advantages. Then it says " A total of 34 billionaires, or 8.5%, scored as 10s".

[Tinyyy]

So given 10 possible rankings, it is pretty well distributed then?

[jacalata]

Well distributed for what metric? Their backgrounds clearly don't match the normal population, since the normal population isn't 7% billionaires.