Sure but I’d still rather not use that as the defining metric. Unless there’s some evidence throwing money at public schools in lower class neighborhoods is the solution to the problem. Every time I’ve looked into that subject in the US the biggest complaint by the teachers on the ground, in those neighborhoods, say they feel like they need to be teacher + daycare + parent for a subset + law enforcement officer etc. I grew up in a small town in Canada with mostly poorer lower/lower-mid class student but my school never had such an obligation (not overt expectation) to be parental replacements/invested psychologist/serious enforcers.

At a pretty sudden level focusing on education alone is the fault not the solution. When teachers actually get to be teachers it seems US schools do just fine or better than most of the world (not simply comparing to subsets of small homogenous European countries).