This is a kind of an oldie—I thought this up and put it together back in 2012—but I think it’s good enough to share online. (If you think it’s good enough to share too, go ahead, but please give me credit.)
Of course, numbers keep on getting developed, beyond K-12, and this chart certainly could continue upwards to the right and onwards, but that would be well beyond me. So I’ll stop here and leave the upwards and onwards to somebody else, maybe even you, in the comments, below.