Actually, you are skewing your results by using the maximum percentage for SSR- which is not even completely built yet and is not sold out. the percentage owned at this time is nowhere near 40% - probably closer to 20% right now.
At this time SSR has 552 villas completed and not all are even in the
DVC inventory. The 828 you are using will include the 6 buildings still under construction (due to open in 2007) - let alone purchased for membership.
The numbers will also change when you use the maximum villas available at each resort, since each has a variance based on the number of lock-offs and how those are reserved thru DVC.
In addition, the owners at VB and HH do play a role since points are used at those resorts by non-owners and those owners also stay at the onsite resorts. The percentages are not very easy to use in this manner since there are so many permutations based on how the resorts are actually used by members- and even that varies from day-to-day.