Do you need to know what Invoices were Outstanding at a particular point in time? Now you can find out using some spreadsheet magic!
Simply create an Invoices Data Export with the Date Range that you need to report on (i.e. 1 July 2014 - 30 June 2015). That will give you a list of Invoices created in that time period. Then, over in column M, you'll find the Date Closed field, like so:
From there, you'll just need to do some sorting and deleting to find the Invoices that were Closed after the Date Range you require!