Score Inconsistencies

I've become really inconsistent on my PT scores. For the last ~7 PTs I've taken over the course of the summer, I've started to jump between mid-high 160s to 170+ basically every other PT. I've scored above 170 enough times that it feels like those aren't flukes but I also cannot tell what is going wrong on the PTs that are on the lower end. Any advice on being more consistent? :)