How to view and download historical reports
From the main reports control panel, click the name of the report of which you'd like to download a historical version.
In the "Report Logs" pane, you'll see a "view" link for each time the report automatically was generated and sent.
Click that "view" link to open the web version of the report as it appeared when it was sent to the email addresses listed.
Within the web report, click the "Download" button in the lower left hand corner to download a PDF version.