From Wiki-
"Possession of non-military-calibre small arms by citizens is largely a non-issue."
"Mexican constitutional rights have long included the right to carry arms."
Registration of small firearms is easy, the permit is issued as a registration card.
Punishment for gun law violations are severe, however.

Since the revolution c. 1916, guns are common in rural areas. I doubt pdq's 2.65 in 100 'statistic'.

On the other hand, the Mexican mindset (are the gangs changing it?) is to avoid wanton physical conflict, and firearms are used only against varmints, and for hunting and pleasure shooting.

Canadians have a similar attitude or mindset, tending to avoid unnecessary conflicts.