Last record number assigned to easyblog_users

I'm using EasyBlog 3.7.13380 and I'm trying to find the table and field that controls the last record number assigned to easyblog_users. I need this because I want to clean up this item. Too many spammers have signed up, which I've already been deleting. I would like to bring down the last record number to coincide with the last VALID user in the database.