The beginning of publications in 2020 can be explained by the fact that after a time (a year or three) the blacklists were dropped, the owner of these Alts came in and saw that the accounts were no longer blocked.
AFAIK once an account is hit with an evil fee it never gets reduced for that account. So even if you log in after two years you'd still have to pay it. Not sure if you register a new account from the same IP if it could get a lower fee, assuming the IP address was not involved in any more bans in that time. But I don't think registering a bunch of accounts and reactivating them later is a viable strategy to avoid the evil fee.
I'll add a couple more columns to the table in the OP that might be more useful - number of users who made at least one post and number of still-active users.