Just to point this out, but... Shipped units is NOT equivalent to SOLD units, which imply "market share". GPUs on store shelves are not getting used and do not represent someone replacing one brand for another. Sure, a supplier bought them, but it doesn't mean that is going to be a trend going forward if they stay on shelves in the long run (just to point out: this apply to all of them, obviously).
If you can find evidence that shipped GPUs correlate 1:1 to sold ones then that would make more sense to me, otherwise this is misleading as heck.
Regards.