That is still not a stat. That is a hypothetical assumption.
Without the amount of miss controls he did earlier in the season for example, we may well of kept the ball, knocked it around better and delivered it to Kone or Naismith, who were far more confident as they would be the main strikers, and not understudies to a kid.
No one knows what would of happened, its not a stat, its a guess. The stats are how many we scored with him, how many without, but that doesn't tell us what the stats would be if we didn't have him.
Certain players up front instead of him may of won us games we lost with him in for example.
Stats are things like....
We are 12th
Lukaku scored x amount of goals
Kone scored x amount goals..
from which assumptions can be made, which is what you are calling a stat.
We simply don't know where we would be. Almost certainly much lower than without him though.