I would suggest renaming the notebook with an insight as the headline is not suggestive of what the notebook really is

Good idea!

Really good that you preprocessed your data in JavaScript but maybe the above task can be done in an easier way through functions like groups and rollup(I recommend you have a look). All the data count shows 0, unless I click on the result. The plot seems to appear only after I execute the above cell, which might be confusing to the viewer as it is not stated clearly. The notebook could have been arranged better, as viewers they might not be interested in data preprocessing code as much as Insights

Thanks for the advice! I didn't know groups and rollup - will do some research on them!