I'm trying to create a KPM widget that displays current performance as a percentage - something like the picture below.

I've tried following the instructions at https://www.zoho.com/analytics/help/dashboard/kpi-widgets.html#chart but nothing ends up being close. Can anyone give me a step-by-step walkthrough using the test data below?

I'm trying to display the percentage of records where dispatch_time is below the target of 300 seconds. The dispatch_KPM is not a required field - this is a formula-generated boolean true/false field that I've included in case it makes it easier to generate the widget.