sorry but this is similar to the ones like : "calculator shows 50% more profit then i get. why is that?"
Not at all like this. It shows not the calculator, but the miner. The calculator does not calculate the profit, but the efficiency of finding shares. So this efficiency is lower than stated. Just want to understand why. If you are used to deal with everything superficially - your right.
Forgive me, doctor

Here you have 2 pictures with arrows, compare, can understand what I'm talking about ....

Good point Sx5000 !
I'm waiting for Dok's reply..
I know you all have your conspiracy theories that a miner must steal your hashrate, but i will have to dissapoint you.
Your math is bad, to get average of something you divide total with something, in this case :
Total time in seconds since connected to pool / total number of sent shares (good & bad)And end of story. This is how you get average time needed to find a share.
Sorry im not stealing 9% of your hashrate.
Your case:
Mining time 15 hours, 3 minutes 10 seconds = 54190 sec (in this case this can be taken because you did not have pool disconnects)
Total shares : 1213
Average : 54190 / 1213 =
44.6 sec
Now check your screenshot.