Cumulative count

[deleted-user-qpvAI3Fo0MKR]

I'm trying to create a cumulative count of IDs by Date in a field called Count.

For example, with these 3 IDs highlighted below, the results of Count would be 1, 2 and 3.

Any help would be greatly appreciated.

*edit - in the screenshot above the IDs have been sorted to be grouped.

[DarrenWiens2 · Accepted solution]

See here for the logic behind tracking the count in a dictionary: https://community.esri.com/message/596160?commentID=596160#comment-596160 

And here for Update Cursor (ideally, your data is in a database and you can use ORDER_BY): UpdateCursor—Data Access module | ArcGIS Desktop 

[deleted-user-qpvAI3Fo0MKR]

Thanks you Darren Wiens‌ for providing the logic! I'm using the Sort tool to bring the .csv into scratch.gdb ready to be populated with the counts using your logic.

Many thanks again!