Using the Transactions feature you can track all imports and exports that happened within your channel.
To access Transactions click on "More Actions" button on projects' page, then choose "Transaction" from the drop down menu.
You can apply the "Transaction Type", "Start Date", and "End Date" filter to view transactions. Just set some values into this fields and click on "Search"
Click on link "Report" to open needed transaction details. From opened export report you can "Remember content" and from opened import report you can re-import content.