Here's the deal. The audit trail can be quite substantial and if you removed the transactions you would also remove the audit trail.  Its main purpose is for tracking all changes over all time. Condensing prior to a certain date creates a single journal entry on condensation. You can and should always keep either an uncondensed copy or at least a backup prior to the comdensing date. Unless there would be a reason to not keep the past year I would condense as of 12/31/18, not 19