What's in a (demographic) name?

Here's the list of the various ways that Washington's Office of the Superintendent of Public Instruction demographically breaks down results of student performance.

In my school, more than a third of students have parents in the military, stationed at Joint Base Lewis-McChord, which hosts several of the units that have done numerous deployments to Iraq and Afghanistan in the last 10 years.  Indeed, it has been my privilege to meet Medal of Honor winner, Leroy Petry, whose children attended my school.

The educational and personal stresses that follow from parent(s) deploying, then returning, are numerous and significant.  And that's on top of the consequences of frequent family moves.  (Last year, I had an 8th grader who said that my school was her 9th...in 9 years of schooling.)

Yet, we take no demographic notice of that.  Not sure I understand that, but, of course, there's much I don't understand.