The Bureau of Labor Statistics ( http://www.bls.gov/ ) is just fascinating enough and just badly organized enough that I never seem to be able to get to the same useful piece of information twice. And thus I constantly find myself looking at other interesting facts about the US labor force.
Making survey data structured is quite challenging and I gained a lot of respect for the work they do.
Anyway, if you go down this rabbit hole, maybe make it an IRL rabbit hole and giving them a call may help get to your answers quickly.