Are the end of month numbers we see every month just a report of the number of contributors he has at that point in time? Or can we see the additions and subtractions?
AFAIK, there is no way for someone who is not the account holder to see any breakdown of patrons, but I'm not familiar with how the site works as I've never been a member. Someone else may know better.
His low point so far was 387 patrons, a number he fell to twice within four months (Jan-Apr this year).
I think we can assume that the vast majority of his increase since then is from new patrons, although it's impossible to know how many of those are people who had previously been following him on YouTube but had not signed up, versus those who are totally new to his channel. At the current number (today down to 503) that means 116 of his patrons are newer signups (since April this year).
Those 116 at least are probably quite volatile as they may feel at any time they are no longer willing or able to give money to support what he is doing. Even those who have been following him for some time but paying nothing may decide to withdraw financial support if they feel it's not worth it or they can no longer afford to do so. Several who began paying him after his begging video said their financial situation was difficult but they were persuaded by his pleadings to contribute.