Battery health is an estimation based upon many factors. While the full-charge cycle count is one contributing element, it is not the only factor. Another factor is temperature; elevated temperatures while using the iPad, or while being stored can, substantially influence battery health.
Apple quotes an iPad's battery health as 80% of its original capacity after 1000 full battery cycles - one cycle being any combination of charging that together sums to 100% (e.g., 50+20+30 = 100 = 1 cycle). As such, on battery cycles alone, you might anticipate seeing a 2% drop for every 100 full charge cycles.
If you have any concerns while your iPad is within its warranty period, you would be well advised to seek assistance directly from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page.
Alternatively, you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:
Genius Bar Reservation and Apple Support Options - Apple