The business scenario is that contracts guarantee a minimum and maximum volume per month. New contracts start, old ones are renewed or are lost. The attached is dummy data generated in Excel with the grey area showing the overall min and max volume per month, the yellow line is the central/average and blue the actual volume showing the undershoot of volume in June & July.
In Power bi I have been able to do this with an area chart overlaid with a line chart but aligning, scaling and duplicated axes makes this solution very fragile. Does anyone have better alternatives ?