This is just a snapshot of how much stock was available.
However, Series S was definitely fairly slow to sell out in some places in EU, being readily available for several hours.
It will be a distant third this holiday I wager.
Series S is still available right now on amazon italy, france, spain, germany.
And that's with a supposedly really low stock.
At least in Europe S doesn't seem to have done well in this phase.
If it's because it's a gimped model that people do not want or if it's not the kind of product people rush to preorder we cannot say atm.