More of these probably hit the ground than people suspect...
It's just rare for them to hit something like a house or a car, even if there are a lot of them. A meteorite sitting on the ground is just a rock to 99 percent of people who see it. A small object is going to be at normal atmospheric terminal velocity when it hits--you won't get an obvious crater from something you could hold in you hand any more than you would if you dropped it from a building.
I was astounded at how little ground damage there was, never mind no injuries, from the debris rain of the Columbia tragedy, but it probably proves the point.