Chart format question: different y axis numerical scales with drill down?

I have a bar chart that shows amounts billed vs. time. From the top level, Year, the user can drill down to Quarter, Month, Day.

The y-axis numerical scale is set on auto and this works fine until the Day level at which point the auto scaling results in a distorted visual presentation. For example, one month might have a particular day with a very high billing amount and the y-axis would be scaled accordingly with a high maximum number, while another month might have only days with low billing amounts and the y-axis would be scaled with a low maximum number. 

If the y-axis on the Day level could be independently scaled to an arbitrary number, this would provide the user with a much better visual comparision, i.e., low numbers would indeed appear low from one month to the next rather than jump up and down with variations in the y-axis.

Any way to accomplish this?