You can download a CSV file for a report by clicking on the Export button. As with running a report in your browser, your exported report will contain the fields you select and include only results based on your timeframe, filter, and search parameters.
To export the report that you generated, click Export to CSV in the top right corner of the report. This downloads a copy of the report data to a CSV file.
If you do not see the Export to CSV button on these reports, then your user account does not have stats exporting enabled.