I'm attempting to build a viz that aggregates a YTD calculated field on a monthly basis. Per the attached sample, I want to calculate a rollup of the average sales per transaction on a YTD basis for each month. February, for example, would use the results of January and February together. I know I can do this by creating a separate calculated field for each month of the year, but it seems like there has to be an easier way.

As per the example, I'm able to use the rolling calculation table calc to derive the appropriate numerator and denominator for the calculation I'd like to achieve. Is there a way to divide one into the other? To be clear, I'd like the resulting calculation to be $118896/1809 for March, $159,008/2537 for April and so on.

Thanks for any help you can provide.