http://digg.com/2018/civilian-owned-guns-graphed
origin - https://www.pipiscrew.com/2018/09/how-many-civilian-owned-firearms-there-are-in-north-america-vs-the-rest-of-the-world-graphed/ how-many-civilian-owned-firearms-there-are-in-north-america-vs-the-rest-of-the-world-graphed