[jmoss20]

Yeah, this is along the lines of my comment. (Am a military brat, attended some DoD schools, also attended a school in FCPS.)

The educational rigor across different districts is massive. Many military kids get to sample from it a lot of times (possibly even with a bias for FCPS in particular!); other kids get to sample it ~once. There is probably some huge reversion to the mean at play here.