Those numbers are generally recorded during the testing phase when expert growers run the seeds through their paces under the absolute best conditions.
They have everything they need at their disposal unlike most everyone else.

I would read those numbers as "this is what you'll get if you really know what you're doing, you have the best equipment money can buy & luck is on your side".

Some breeders are honest enough to say that it's under those conditions and give two numbers - one for the typical customer & one for experts.

However, if this is your first few times out and you're still figuring out what to do, no one can guess at what will happen.