Reports not adding up

Reports not adding up

I have a subform that we add lines for costs. These are added up in the aggregate (see image 1). When I pulled these into reports, I link the aggregate subform cost, but it keeps adding each subform line, instead of just the PO Subject and the numbers are confusing (see image 3). I dont have any links to the subform other than the aggregate.
Then I added a separate formula box with the subform aggregate copying to that, and linked this to the report, but it does the same thing (see imaeg 2). 
Anything know how I set these reports up so the total of the PO Subject shows the total subforms, without listing every line in the subform.