How many people are unranked?

I know how to find statistics on ranked players, but I was wondering how much of the playerbase is unranked (in terms of %) or if there is some source to find it. I haven't found anything yet.

Reason I'm asking is that I just assumed that like 85% of people playing LoL play ranked at least somewhat regularly (like monthly) but recently I have run into a bunch of people who just never do in real life, I guess I never get matched with significant numbers of unranked people in normals.