Admission rates make no sense

[Daarkness]

I have been looking at admission rates for PhD in mechanical engineering at the top 60-ish in order to maybe us that as a tie-breaker when choosing where to apply to. However, almost every single one hover somewhere between 11 to 18 percent regardless if its MIT or Penn State or a UC. There's no pattern either, it's not that the top ones are lower even within this narrow range. Am I missing something? Do they reject just to keep the numbers low?

[Bird Vision]

People self-select out of higher universities. I did this, as I knew there was virtually zero chance that I'd get into MIT, so I saved my money. Also, this can be calculated in different ways, so the statistics aren't as comparable as you might think.