The article I linked in a sibling to your comment sources several versions of this calculation in the footnotes, though I'm sure there are others as well: https

The article I linked in a sibling to your comment sources several versions of this calculation in the footnotes, though I'm sure there are others as well: https://www.bloomberg.com/view/articles/2015-09-03/should-donald-trump-have-indexed- https://www.bloomberg.com/view/articles/2015-09-03/should-do...