Comment by tzs

Careful looking at their graphs. If you don't keep in mind that they are showing changes you could get a wrong impression. For example on the page they link to to get data from every state, https://edunomicslab.org/roi-over-time/ , it shows the graphs for Massachusetts and Mississippi side by side.

In Massachusetts 8th grade math is down about 17 points. In Mississippi math down about 2 points. (I'm using 2022 scores).

That could give the impression that math scores are higher in Mississippi since the math line on the Massachusetts graph is way lower than the corresponding line on the Mississippi graph.

But the actual scores those years were 284 for Massachusetts and 268 for Mississippi.