Embedded report - size of data served

Greetings. Hope this isn't to obvious a question. We are doing load testing on our Power BI embedded application. For the sake of argument, lets say our published report is 20MB. When requesting the report through my application (using row level security) the amount of data returned is a very small subset of the total data - say 1,000 rows.

Is there any way to determine the total amount of data that is being sent to the client - in terms of kb or mb?