Looks like polar coordinates, with theta being the maleness (at 180 degrees) or femaleness (at 0 degrees), and radius being the magnitude.

(edit: That’s actually what it says above the chart, I just missed it.)

In the US, healthcare is too expensive to afford out of pocket, so most people get health insurance from their employer, as an additional benefit. This covers the employee, their spouse, and their children up to a certain age.

In this case, it looks like people employed by the military will be prevented from getting full healthcare for their children, if those children are transgender.