?

Don't know if it helps, but can you search against Grant Date, rather than Filing Date? My thinking is that Grant is almost certainly going to be after product release, so maybe it's a narrower range. During development, there is often little time to do the patent stuff. But closer to Release time, the designers (may) be less busy, the design details are firm, and they can think about patentable stuff. I could be wrong...

Trivia: My career was with DEC, then with HP and HPE. DEC was "stingy" about spending money for patents. In the late 80's I submitted a Disclosure as an employee of Manufacturing. DEC said basically "good idea, but in Manufacturing we can just keep it a secret, so no need for a patent."
But HP was very generous with patents. Simply submitting the disclosure paperwork paid the employee $100. If the patent was actually granted, they paid another $1000. I got two in my career (8184982 and 8648568) - the second one took 4 years until it was granted (but it was submitted first).

Pete