With the uncertainty of relatively few serial numbers being reported it seems USA deliveries may be running about 10% higher than for the EU/UK
And I saw a Canadian Z9: 400095*. Not sure how new that one is, but it seems to confirm that the Canadian market is roughly 10% of the size of the US.
Your 10% for Canada relative to USA seems reasonably accurate.
Several serial numbers posted on this forum fail to reach the photosynthesis site.
This unfortunately introduces elements of guesswork working out actual numbers and market share.
Globally, Nikon must have shipped close to 40K Z9 in about 6 months
Ricci mentioned about 3,500 units a month about 6 months ago.
It is likely Nikon started producing Z9 month bodies about two months before actual delivery, adding final firmware about two weeks before delivery.
This makes around 40,000 so far in customers hands a reasonable estimate.
That is a lot for a flagship body.
For a current Nikon flagship body - yes.
Another trend I noticed is that some intermediate photographers are getting the Z9, not merely pros and advanced amateurs, based on the questions asked on various forums, e.g. here and on Facebook. Some of those are more basic questions that I would more associate with e.g. D3500, Z50 owners. Perhaps the $5500 price tag, while still high but less than other flagships such as the Sony A1, Nikon D6, has broadened the Z9’s appeal.
Most cameras in some respects can outperform the photographic capabilities of their owners.
I get the impression from some questions asked that a few Z9 owners can achieve little more than 10% of what a Z9 can.
This must be frustrating to highly skilled photographers waiting in the delivery queue