You can't really do that because there is no way to know how much someone is worth. What is my house worth - there is no answer until I sell it. You know what it last sold for, but you have no idea if I fixed it up since then so it is worth more; or maybe I was cooking meth and now it is a toxic waste site with negative value. A house is simple to value compared to a business. A yacht is another asset that is really hard to value.

For public stocks we can at least calculate value with computers, but for some that is a minority of value. In 1960 the DOW was used because it is only 30 stocks so you can add the values up every few minutes - the S&P 500 could only be calculated at the end of the day as by the time you got the value of the last stock the value of the first had changed.