How to check % of User Profile completion

And again a very special question. I want to push users to finish their User Profile and Fill all the values after registration.

What I’m doing now is to ask only a few minimal questions for User Onboarding. But then I need to tell them on their User Dashboard that they only filled : 60% of their Profile. That would force the user to complete their profile. But not sure how to properly handle that. I mean columns like, Street, Phone, Adress can be checked for NULL values. But not sure how to handle that into a single MySQL query. Maybe go with JSON and handle that with expressions? Or maybe purely by SQL Statement? @Hyperbytes I guess you know that