You can scroll back to the inception of HIVE, was it mid 2020 something? Anyway, you can easily find the start where Steem transfers switch to Hive

https://hive-db.com/@rok-sivante/transfers

And furthermore - if possible/allowed with you tax office, declare only the transactions where crypto is exchanged into fiat. I know our local tax office here in Estonia required all kinds of silly data, like all minuscule Steem transactions, but have settled with with the 5-6 instances where I have withdrawn BTC to Coinbase and sold it for EUR. In this case I only declare the EUR value of BTC at that moment when the transfer hits my Coinbase account. Have done it for a few years and probably they are happy that I try to be as accurate as humanly possible declaring volatile crypto, which actual value is in some cases highly questionable. Good luck to them should they decide to hunt down everything (they won't)