Unfortunately, the inventory history is not exposed in the Shopify API, so this is not something EZ Exporter can export.

The API only provides the current inventory quantity at the time of export.

However, what you can do instead is schedule a daily automated export of current inventory levels from your Shopify store with EZ Exporter.  This way, you'll have that export history/backup you can go back to at a later time to check what the previous inventory levels were.