They have a bit on that kind of thing on the site ... iirc ... lemme see if I can find it for you... alas, no, failed to find from skim reading its menus and https://politicalcompass.org/about , https://politicalcompass.org/faq , and other pages... I was sure they had a bit about where their center was, along with how their statements are weighted in the test, and how worded, and why they don't change it.

Also, measuring it by a popularity bellcurve would reduce its meaningfulness and utility. It'd make weather-vanes of far more of us, leaving fewer sign posts.