Any create or change action for any object (material master, purchase order etc.) is stored in database tables - CDHDR and CDPOS. You need to search those tables.
For creation of new record - CDHDR field will be set as "I" for insert
For updation - the same field will contain "U" for update
I am forgetting the technical name, just look up this table, you will find your answer.
You can also goto Environment -> Item Changes by using MM03 tcode. It will show all master data create and update records. You can analyze accordingly.