The task distribution pie chart in Analytics is a valuable asset when you want to see on the whole (no time ranges) how much of your work is of a certain type, how many cards are labeled with certain tags, where most of the time is being logged, etc.
For better reporting of the information across the whole account, project or board level within a relative time range, you can use the Advanced Search panel (the magnifying glass icon).
Click on Refine search criteria to open the Refine search criteria panel.
Select your search criteria to narrow down your search: Board and Last modified -> click on Add.
Select a board from the drop-down menu. You can add extra boards by clicking on "or" and selecting the name of the board.
Go to Last Modified -> set the filter by choosing an option: is / is not / before/ after / is between -> define your time range -> click on Search.
The system will generate a report with all cards that belong to that board. Use the "Configure results" button to extend the information in your report.
Each selected tab will be represented as a new column in the report - select Cycle Time to have it present in your report -> click on Apply changes.
Click on the column name to sort the results in ascending/descending order.
Using the visualization options, you can choose to visualize the data from your search in a Pie graph and slice the data by certain criteria.