Help! Multiple Chart Data Update Automation

Hello!

I am working on a workbook that includes data related to call center employee performance. The workbook has a separate sheet for each employee, and each sheet has that employee's data. There is a visual chart that pulls data from the same sheet to show the proportion of different kinds of work done. Each month, there is new data that the chart should pull from. At this point, I have been needing to go into each sheet and manually re-select the data for the chart in order to change it.

My question: Is there a way to set up a macro (that will work the same across each employee sheet) that will automatically change the data source to the cells containing the new month's data?

Please help if you can!