NPC reward behaving differently than expected

[zocke1r]

While grinding a particularly unrewarding npc for a rare card drop i noticed that the reward stats doesn't behave as i expected. Instead of being the mpg gain against that npc it's appears to be the sum of match rewards without considering the match fee.
Example: match fee is 30 mgp, lose gives 9, on a lose mgp goes up by 9 instead of decreasing by 21.
I think for it to be more useful as a statistic, the match fee should also be considered. Or a tooltip should be added that the value does not include match fees