Rebs: It would be expresed as + or - 1/10
You would not be more than 1/10 off your baseline.
You could be as much as 2/10 off between rounds of course.
The whole thing gets mucky, when I am doing load runs, I use 5/10 between the lots to ensure there is a large enough variance to see.
I will test down to 3/10 but no closer.
I don't have the references but that seems to be where a change occurs is at about 3/10 above or below specified charge.