Usually, you'd use a plugin to get this information quicker, but we've found out that there are some damaging plugins out there that slow the performance of your site.
Here's how you can do it using your backend and a little bit of AI.
Log in to the backend and go to the 'export data' tab.
Click 'export order with customer'
Set the dates to the date you went live to now.
Download the export.
Ask AI to sort the total spend from highest to lowest.