Case of the Single grape ?

I have  had the fortune and misfortune of having my destiny and career tied to commercial airlines for the past 14-15 yrs or so. That has meant plenty of trans-atlantinc, trans-pacific, and local domestic Indian flights. And on all these flights, I have endured the food and survived. 

There is this one thing that has continued to stump me. Its the case of the single grape. If you have observed closely, the fruit bowl that you get with your meal will always (my experience is 99%) contain one single grape. And it will have pips (seeds) in it. And in 90% of the cases, the grape will be sour. 

Is that just a coincidence ? There must be a grater conspiracy in play here. Its my belief that its the airlines playing mind games with us. I am now going to start documenting this. I need a new facebook campaign. "We need atleast two grapes"