Not for sure. Liz probably knows.
Think from a short search, between 40-42% of Americans say they have a gun in the house. Not sure how many do not admit to it.
Sold a couple and lost the rest.
A 2018 Small Arms Survey found over one billion small arms distributed globally.....857 million (about 85%) are in civilian hands.
The Survey found US civilians alone account for 393 million (about 46%) of the worldwide total of civilian held firearms.