Very, very nice summary. I would point out, however, that families with very large sums of money typically care a lot about not disclosing their wealth, particularly that has been wealthy that long. Their wealth is spread out through a myriad of unrecognizable entities and secret accounts I am sure. Particularly a family who had tried to stay out of the limelight as you suggested they have. Some wealthy people like the notoriety so they make more of their wealth known, others are much more stealth. So, it's truly very difficult for anyone to accurately quantify the wealth of many of the worlds wealthiest people/families.