<p>I don’t have a published source. From what I know admitted students from China and Canada last year (Class 2015), this has been the case. A kid who made the Canada IMO team did not get in. Look at the link below and China has 8 students per year on average and India has 6 per year who got admitted to MIT. Those countries have much more IxxO medalists than admitted number.</p>
<p>[MIT</a> | The International Students Office | Statistics 2009 - 2010](<a href=“http://web.mit.edu/iso/stats_09-10/general.shtml]MIT”>http://web.mit.edu/iso/stats_09-10/general.shtml)</p>