Okay, this happened to me, um, about five minutes ago. I've been carrying groceries up and down stairs for years now, and the stairs in question for about 20. This time however, the bag ripped, and fell from my hand. I wasn't carrying it "properly", and though I've lost my grip before, I've never actually dropped them to the ground like that. Accordingly, Murphy's law required that the bag in question contain eggs, a fact that became obvous as it lay sideways on the floor, oozing a mix of clear and yellow slime.
There are two questions to this post. One, how often have you dropped a bag of groceries, for whatever reason. The second question, how often has it contained eggs, or some other impact sensitive item?
Rough estimate: Twenty years @ about 2-3 weeks per egg trip (I do quite a bit of "from scratch" cooking) = One out of about 400 trips = 0.0025 = 0.25% failure rate
BTW, 7 out of 18 eggs survived, and considering the impact, that's pretty impressive, as they're only packed in styrofoam that's about half as thick as when egg cartons first began to be made with it.
Looks like omelets tonight.