Hi @KSOL
Thank you for your question. As per current design, when you set-up export as per the given interval and shared storage account the reports will be generated for each month.
However, you are welcome to share your feedback here: https://feedback.azure.com/d365community/forum/79b1327d-d925-ec11-b6e6-000d3a4f06a4
Regards
Divya