Right. When you have 10,000 employees, then you are quite likely to experience something only one out of 10,000 people would do. Multiply that over several year

Right. When you have 10,000 employees, then you are quite likely to experience something only one out of 10,000 people would do. Multiply that over several years, and low probability events happen with surprising (at first glance) regularity. The classic example of this is that on Google's main campus there are tens of thousands of workers. That's the size of a small town. So one should expect medical emergencies at about the same rate as a small town--which is to say, several every week. You should expect ambulances and fire trucks and what not else regularly, not unusually.