Inventory Aging Report

I’m currently making an Inventory Aging Report and my valuation is FIFO (Manage by batch). I used table IBT1 to get all IN and OUT transaction.

I need to know the right table where I can get the Item Cost especially for transactions CM (Credit Memo) and IM (Inventory Transfer).  Where does SAP base its Item Cost on Inventory Audit Report? Right now I’m using OINM table for Item Cost.