Using the transactions feature, you can track all imports and exports that happened within your channel. 
To access your transactions, click 'More Actions' button on the projects page and choose 'Transactions' from the drop-down list.

You can apply the "Transaction Type", "Start Date", and "End Date" filter to view transactions. Once you define the search filters, click 'Search'.

Click 'Report' to open the details of transaction in question. In the export report you'll be able to "Remember content" and in the import report - to re-import it.