<p>There is a much simpler answer here –</p>
<p>I read there are 19,500 high schools in the U.S.</p>
<p>Yale accepts about 1,600 - nice number! (not 19,500+ if it took one from each school) students per year, of which about 70% attend.</p>
<p>I would guess of the 19,500 schools, Yale actually admits a student from about 1,200 distinct schools each year, with about half of those 1,200 changing each year), and as many as 20 from some famous feeeder schools.</p>
<p>In sum, Yale accepts nobody at all from about 95% of schools in this country in a given year.</p>
<p>Our local high school (500+ grads), sent nobody to Yale in 2006 instead two to Princeton, and for 2007 three to Yale, but none to Princeton. Harvard is about one every other year, same with Caltech. Stanford same as Yale and Princeton, one year on, one year off. MIT seems to get 1-2 every year. About 25% of those are (excepting Caltech, MIT) athletic recruit admits in baseball, football, volleyball, etc.</p>