Days Gone side quest scores

On NERO Check points and killing Hordes I find myself completing them and always getting between 16%-90% and I keep wondering how and why I keep getting these seemingly random scores. How can I score higher on killing a horde or clearing an ambush camp or a Nero checkpoint. If anyone can answer this it would be greatly appreciated, to ask formally, how can I score 100% on a horde/ambush camp/Nero checkpoint?

What you see is called Storyline completion percentage. Storylines are usually related to story, some characters or open world activities.

The is global value and is updated once you complete some activity for this Storyline, to get 100% you will need to complete all such activities. Sometimes they are blocked behind some story missions or encampments jobs (for example, some Ambush camps will only appear after you take corresponding encampment job).