A data point: I was raised up in a tier 2/3 city in northern China, finished high school at about 2013. I'm not exposed to calculus or linear algebra at all whi

A data point: I was raised up in a tier 2/3 city in northern China, finished high school at about 2013. I'm not exposed to calculus or linear algebra at all while in high school. OTOH, friends of same age who were in Shanghai did get exposed to linear algebra.