Wikipedia's (UBS') US figure ($69k) is probably wrong? US median household wealth is ~$193k[1]. I don't think there's a way to square claimed median individual wealth of $69k with that? Even taking into account children (22% population) and assuming 2 adults/household (more favorable to the math than the real 1.2-1.4 figure). I can't find anything on UBS' methodology, just the short 1.5 page paper.
[1]: https://www.federalreserve.gov/econres/scfindex.htm