Thanks for sharing, I would say that each school handles the wait-list slightly differently so you want to make sure you follow the protocol outlined in your wait-list letter. Some schools welcome updates others do not so you want to make sure you don't go rogue during this anxious time. There really are no percentages or ratios for the wait-list and if there was it probably would not be helpful. My best advice is to figure out the logistics for your school specific wait-list process then work within that structure to counteract any question marks or showcase improvement since your application submission.

Hope this helps!