Hi Rav - so I took a look and actually based on the definition of that stat it appears to be correct:
Topics created in the last 30 days with no employee replies but have topic status = 'Solved/Answered'
The only topic created in the last 30 days that fits that bill was created by you, and we also don't count employee-created topics in that stat but that's not explicitly stated.
I looked back a bit further and saw that you had much higher instances of self-service in January, then a bit less in Feb, etc until basically zero now. My guess is that that means in general your employees are being more responsive to every post that comes in. Does that sound about right?