You may be interested in: Applications and mapping algorithmsAFAIK 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.
Probably this happens only in those cases when the account itself is banned, then you will have to pay a little for registration or activation through the same IP address.
Below is a quote that I understand as confirmation that it takes time for the IP to turn white, This probably only applies to IP addresses that have not been associated with evil in the future. Unless the accounts are blacklisted or permanently blocked, this can be a viable strategy to avoid being charged.
Do evil points ever fade away
Yes. This map is pretty short-term. And I'm probably not going to update it. But it's still interesting IMO.