Oh? The manufacturer's don't know how many sleds they sold in year 2017 up to this point? I bet they know the exact number.
ISMA is just where they release all their info to the other manufacturer's.
Against my better instincts, I'm compelled to reply this one time, so others get an idea of how this works in the OEM industry, if they are interested.
Firstly, of course they know the shipping status of their own sleds (Ski-doo#1's response above is a false argument, intentional or not. I, and no one else, ever said they don't know their own ship statuses. Sloooow down.
What they don't know up-to-the-minute is the status of their competitor shipments, in total, by segment, or model.
ISMA is the International Snowmobile Manufacturers Association. Up until 15 years ago, the OEMs did not share any model breakdown unit sales information with each other. None, nada. Info as total units, at best - the rest was tribal knowledge, picked up when they hired each other's people, bragged to a magazine, etc. In the early 2000's they realized they are in this together (about the same time as the Blue Ribbon Coalition), and started to share model unit sales information through ISMA. They took the cue from the auto industry. It's voluntary and on the honor system, as in, no audits, etc. But, there is no "authority", and there can be delays in reporting, etc. When you are counting beans, best to wait until the bag is empty before you're done counting.
Ski-doo#1's statement as of Feb 15 could be dead on, and apparently he/she has some knowledge of the ISMA bean counting. If you're interested in how the beans were counted, hope this helps. Carry on, ride the color bean you like best...