The charts are free. Take them.

Every chart, plate, and figure published in the essays on this site is free to reuse in articles, decks, newsletters, and posts, commercial or not, as long as you credit the source. (Documents shared by private link are not covered; those stay private.)

Credit it as Malcolm Angus, malcolmangus.com, with a link to the essay the figure came from where the format allows one.

That's the whole license. No permission emails, no forms. If you want a version in different dimensions or a format I don't publish, send a note and I'll usually just make it.

Why free? Because published, citable measurement is the strategy: give away the scoreboard, sell the fix.