Monitor ALL new sign ups to your group
Get a weekly summary report emailed to you
Click on Report
Scroll further down the left hand column and pick (for example) all sign ups in the last 7 days.
Click 'Save and select data' blue button on bottom right.
Choose which fields you'd like to see in your report and what order you'd like to see them
Click 'Save and get results' button
Note : This may take some time to load!