Well observed, I didn't think about this when writing the title. It's too late for me to edit the title, but I think "20 000" would be a good option. (The wiki

Well observed, I didn't think about this when writing the title. It's too late for me to edit the title, but I think "20 000" would be a good option. (The wikipedia article advocates a thin space as separator.) I would appreciate if someone could change this, since the majority here is probably American.