KieranVinomofo Member

 Thanks BrendanH. I ended up doing a SUM group by (on amount charged, grouping by the cohort group and month & year of order) in my magic ETL after doing the rank & window. It means I've lost the transactional level detail if I want to drill further into the data, but it's given me good aggregated data to show each…

Thanks! That worked a treat, really appreciate your help!