I don't think there are public numbers. No doubt IBM knows. I do expect that trend to reverse this year if true.

https://www.lto.org/2025/07/lto-tape-technology-shipments-sc...

https://www.theregister.com/2025/07/23/lto_2024_tape_shipmen...

Unless something is wrong with these numbers, it's simple enough to do rough math to get tape count and compare with historical numbers.

Claims of 5.7 or 5.8 million drives over the lifetime of the format can also be compared to older data to see a slowdown.