I agree, but I have seen worse. I believe Altmore goes back several years before that even, and then some of his latest (newest) data points are 2016-2017. And he claims that his analysis is all encompassing.Going back to 2013 is irrelevant data and pointless.
Personally, I think so much has changed in a decade that looking at a decade old data is irrelevant too, but some claim that it shows fluctuations that way. But if you look at that long of a data sample you have to take into account the trajectory of the data, whether it is flat, upward, or downward, and no one is doing that.
I personally think that trajectory is more important than average. If School A's stats are on an upward trajectory, and School Bs is on a downward Trajectory, even though, they average the same. The one on the upward trajectory is more valuable, because they are moving in the right direction, and increasing. But no one is looking and showing that data point. Because it doesn't fit their narrative.