Calculating employee performance by quartiles every week

[diegof1]

Hi Looker fam,

I have the table below that shows the contribution of each of my employees since they started, week by week. I’d like to see performance per quartiles in every week, for example: the employees who generated most “contribution” (top 25%) generated $15,000 on average by week 4, $20,000 by week 5, etc. The employees that generated less contribution (bottom 25%) generated 0 by week 4 on average, $5,000 by week 5, etc. How can I achieve this through LookML? And through Table Calcs?

Thanks a lot