This level of fragmentation is a bit of a non-entity, the max file fragments in your image is 6 and that really isn't big by any stretch of the imagination.
This only looks like a big deal because you are only looking at the avast folder and these files would change daily so fragmentation is always going to be there.
Defragging just my firewall program folder and avast doest even feature in the next 10, nor does it appear the next 10 after selectively defragging those specific folders.
So you shouldn't really take these things in isolation, defrag today and you are likely to see the same fragmentation tomorrow as that is the nature of volatile data. This in no way impacts on my system runs just fine, if I defragged them, tomorrow it is likely to be the same and overall my c:\ drive has 3% fragmentation on 225MB, this is minuscule.
Looking at it in context of hard disk fragmentation and you will see there are bigger fish to fry, avast! doesn't have any file feature in the top ten fragmented files. My firewall takes eight of the top ten (first 6 and last 2) and my mailwasher anti-spam takes one and thunderbird the other one.