The US Federal Government use three general counting methods to collect data:
The Data-Planet Libguide offers detailed information on how to use the resource. From the different datasets available to how to manipulate data. If you not familair with Data-Planet take a few moments to learn some of the finer points.
Data-Planet opens one door into a whole bunch of data! Users can search and browse through 35 billion data points in over 4.9 billion datasets sourced from over 75 public and private sources, covering sixteen subject areas, and nearly 500 databases. The powerful functionality of the Data-Planet platform allows users to get the data they need fast.