the only answer to this question can be given as anything could be happend(sorry for not being exact)

as this time rank was given acoording to the percentile so a major changes can happens

my friend got 99.3 percentile and she got about 19000 rank and she has scored about 167 marks.for this  marks the last year ranks were about 15000 or less.some has saw opposite trend also ie get less rank with same percentile so anything could possible but yes changes are there but whether it is drastic or not cannot be said