How to set up statistics generator in existing project?

[cdauth]

I have discovered the statistics generator addon and would like to make it push the statistics into my repository as a JSON file so that I can show the translation progress in my UI. I have followed the instructions. When a translation for a particular language is created/modified, a statistics file for that language is now pushed as well, which is good.

However, what about the existing languages where no modifications are being made right now? Can I somehow manually run the add-on so that it creates the statistics for all the existing languages?

Also, the examples show how to create one JSON file per language. Is it also possible to create a single JSON file containing statistics about all the languages?

[nijel]

#17475 should make this automatic