Location of Tax Recovery Rate used for requisition or Purchase Orders in data tables

Summary:

I'm trying to find where in the data tables the Tax Recovery Rate used on a requisition or a Purchase Order is stored.

Content (required):

This is the Tax Rate Code setup on the 'Manage Tax and Tax Recovery Rate and is used when a requisition is raised and determines the split between Recoverable and Non Recoverable Tax.

This is needed so we can review requisitions and Purchase Orders on raised on the system and check them against the recovery rate used on invoices matched against the Purchase Order