My guess is that you can put the bar for "wealthy" as high as necessary to get any percentage you want. Illustrating by reductio ad absurdum, you can make the argument that 100% of "wealthy" parents have no wealthy children, if your definition of "wealthy" is only the single richest person in the world. Expand the definition incrementally, and you can probably get nearly any percentage statistic you want between 10% and 100%. So the fact is "not even wrong" without more context.