SO_SalesHistory mismatch

Hello,

I'm running a simple cross-tab report in crystal reports out of the SO_SalesHistory table. The objective is to simply get sales by item, by month.

For some reason there seems to be a mismatch between the SO_SalesHIstory table, and the history tab in item inquiry.

Why would there be a discrepancy between these two areas, and which one is correct? I get that technically the SO_SalesHistory table says quantity "Shipped" and "Returned", but these should match what was "sold". Any thoughts?

A quick example...

April 2017

Item: ABC, SO_SalesHistory says shipped 296, returned 7. Should leave me with a net of 289. Item inquiry history tab shows 292...

Any thoughts? Maybe I'm just misunderstanding what this table is representing?