Hi @cheiligers, thanks for your reply. The issue we have is that we need to make a ration between data of a month and data of a month before. It is like in your case for each carriers you want to do the ratio between number of ES-air of Aprile / number of Logstash airways of march. How I can do it? A ratio will works in each group by cluster, so it will consider only the document of ES-air or of Logstash airways, because of the group by