The biology section (as i had heard) was pretty straightforward so this means that a large percentage of the Medical Students who give the SSE test do get in .
Since these ppl have no interest in research oriented Biology (Courses) they usually do drop out and more vacancies open up.
Secondly, many of the first 200~250 students who receive an offer in the first batch already have admission offers from Universities abroad so they naturally prefer them over LUMS SSE. As a result even more vacancies open up.
Thirdly, since the fees is Rs. 2.6 Million , many of those who do receive the offer in the first batch, they reject it due to financial constraints . Consequently , some more vacancies open up.
May God help all of us