I remember being on a field trip in 6th grade to the museum of science and they had some exhibit that was a counter very similar to this. Some big display that gave population, deaths, people coming in out of the country. Simple stuff.
Everyone was in awe of it. How does it know?! Well I knew it was just based on averages, even then.
Now you can get look at these things with far more detail, right from your own home.