If the plugin satisfies your needs, then use it.
Alternatively, you could export grades from the grade book, then in a product like Excel, create your bar charts. This alternative would give you a lot of flexibility, but you would need to know how to use Excel (or some other spreadsheet program.)
Alternatively, you could export grades from the grade book, then in a product like Excel, create your bar charts. This alternative would give you a lot of flexibility, but you would need to know how to use Excel (or some other spreadsheet program.)