I doubt there is any way to get official numbers, but my anecdotal experience is that perhaps the season ticket holder churn isn't quite as high as we would expect it to be. I have had my Season Tickets for 10 or 11 years now and every year there is a "relocation event" where we can log in and change or upgrade our seats to any other available seats. I don't really have any intention of changing my seat location, but every time I check the options there are very few seats available anywhere. The Cubs are "supposed to" complete seat relocation for existing ticket holders before they offer seats to new people, but I question whether that is actually happening. Honestly though, I question a lot of things the Cubs do (or don't do) for their Season Ticket Holders. But just going by how many seats I see available for relocation, it doesn't appear there are many new seats available from year to year. I do think they have been allowing people to downgrade from full season to partial season packages in some instances, so maybe that is a big part of what has been happening rather than people dropping the tickets altogether.