[Marlo]

I think it is in this ratio:

Hours Worked : Current Available Points/Level

So, If you are Rank 4 engineering, and are 1000 points into it, and have never spent a single point on repairing a hideout or stat gain, then, you will have a higher efficiency than someone who is 1000 points into rank 4 engineering who has used even 1 CP to repair or for stat growth.