I've made no assumptions...the chart is self-explanatory
Yeah, you did, and no, it isn't.
You assumed that all of your readers would know that the heading "Readability Formula Grade" referred to a "Grade Level" when only one, the Flesch-Kincaid, specifically states that. I'm not sure how I'm supposed to know that the others are "graded" the same.
It was only after I compared the other numbers in context that I assumed they all referred to grade level. And it was still just an assumption on my part -- you did not explicity tell me. See what happened here? Because you made an assumption I had to do extra work to reach my own assumption. And if this weren't a forum format I would have no way of knowing if my assumption was correct.