Currently, this reporting is not available within our Community Metrics or Lithium Social Intelligence. I highly recommend voting on this idea and putting a comment on how you'd find this useful: https://lithosphere.lithium.com/t5/Li-Product-Ideas/Reporting-on-Subscriptions/idi-p/4444
It would absolutely be beneficial to see this data and get a sense of user subscribing behaviors.
It drives me crazy when I see Lithium themselves admitting these are must-have features, yet the answer is "Go look at this idea from 2009". It's from 2009, let's be real, if it hasn't happened in a decade, why are you still encouraging us to go vote for it?