I had a math mistake to start out with used 2000 in my head instead of 2020 so do realize that was the reason.
But if you don't think about or make an addition mistake as I did, and and add newer information to the bio--your have no way of protecting it or removing it.
You can't make it semi private it and it is impossible to remove them from the change history.
They remain in the history even if you delete them.
I have tried it should be possible to either over ride or remove newer information from the bio without it being shown in the changes