aggregations not using all classifications in a workflow+version

[vrooje]

Doing further checks with the aggregations from GZBL (project_id = 3), I noticed that 9 subjects that definitely have classifications in the raw classification exports don't have any aggregations at all. Their 300 or so classifications were collected over the past year or so, so they should have shown up in the aggregation of at least the initial task (which I requested after all subjects were retired), but they don't.

This made me worry that there were other classifications missing, so I added up the num_users column in the aggregations file for the initial task in my main workflow (workflow_id == 3, for which the only version is 56.13), and came up with a number that's about 3000 classifications short of the actual raw classifications for that workflow+version.

Where did these classifications go? Why weren't they included? I know it's only at the 1.5% level but we shouldn't waste those. I extracted drawing tasks from them, and that's the last task in the workflow, so I don't currently have reason to suspect they're malformed or incomplete in some way. But even if they are bad or for some other reason couldn't be included, we need to message that and explicitly say which classifications were and were not included in the aggregations.