Look at the interested transaction counts in the block headers. You can take some sample block dumps and extrapolate, or you can infer the number from the space usage statistics in the data dictionary after an analyze. Have a look at the script suggest_table_freelists.sql on the Ixora web site for an example of how to do that.

I'm optimizing parts of my database, and have found some heavily hit tables that I feel should have their freelists increased. I know I should set the number of freelists to the maximum number of concurrent users of those tables ... but how do I figure that out?