If you specify any of the following fields in the Graph contents section of a chart's settings, you will only be able to select Table under Chart type.

• Date
• Time
• Date and Time
• Created datetime
• Updated datetime
• Calculated (If Date & time, Date, Time, Hours & minutes, or Days & hours & minutes is selected as the display format)

If you want to display your aggregated data in a chart of another type, consider using one of the workarounds described below.

• Export the aggregated data in table format to a file. Then, import the file data into the Number field of a new app and convert the data into a chart other than a table.
  Make any necessary changes to the exported file before importing it.
  Exporting an aggregate result to a file
  Creating apps from Excel files
  Creating apps from CSV files
  
  
• Export the aggregated data in table format or the record data to a file, then use a different tool (e.g. Excel) to create a chart of your choice.
  Exporting data to a file